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cr\ 



2007 

California 

Mechanical 

Code 



California Code of Regulations 
Title 24, Part 4 

California Building 
Standards Commission 

Based on 2006 Uniform Mechanical Code 




® 



^ 



EFFECTIVE 
JANUARY 1, 2008 

(For Errata and Supplements, see History Note Appendix) 



Copyright to 2006 UMC® Held by 

International Association of Plumbing and Mechanical Officials 

5001 East Philadelphia Street 
Ontario, California 91761-2816 



Copyright® to all California State Provisions 
Held By 



California Building Standards Commission 

2525 Natomas Park Drive, Suite 130 
Sacramento, CA 95833-2936 



First Printing, iVlay 1 , 2007 
Printed in Tiie United States 



PREFACE 

This document is the 4th of 12 Parts of the official triennial compilation and publication of the adoptions, 
amendments and repeal of administrative regtilations to California Code of Regulations, Title 24, also referred 
to as the California Building Standards Code. Part 4 is known as the California Mechanical Code and incorpo- 
rates, by adoption, the 2006 edition of the Uniform Mechanical Code of the International Association of 
Plumbing and Mechanical Officials with the California amendments. 

The California Building Standards Code is published in its entirety every three years by order of the California 
legislature, with supplements published in intervening years. The California legislature delegated author- 
ity to various State agencies, boards, commissions and departments to create building regulations to imple- 
ment the State's statutes. These building regulations or standards, have the same force of law, and take 
effect 180 days after their publication unless otherwise stipulated. The California Building Standards Code 
applies to occupancies in the State of California as annotated. 

A city, county or city and county may establish more restrictive building standards reasonably necessary 
because of local climatic, geological or topographical conditions. Findings of the local condition(s) and the 
adopted local building standard(s) must be filed with the California Building Standards Commission to 
become effective and may not be effective sooner than the effective date of this edition of California Building 
Standards Code. Local building standards that were adopted and applicable to previous editions of the 
California Building Standards Code do not apply to this edition without appropriate adoption and the 
required filing. 

To familiarize yourself with the format of this code, it is suggested that users review the following contents: 

• How To Distinguish Model Code Language From California Amendments 

• Matrix Adoption Tables 

Should you find publication (e.g., typographical) errors or inconsistencies in this code or wish to offer com- 
ments toward improving its format, please address your coniments to: 



California Building Standards Commission 

2525 Natomas Park Drive, Suite 130 
Sacramento, CA 95833-2936 

Phone: (916) 263-0916 
FAX: (916)263-0959 

Web Page: www.bsc.ca.gov 



ACKNOWLEDGEMENT 



The 2007 California Btiilding Standards Code (Code) was developed through the outstanding collaborative 
efforts of the Department of Housing and Conraumity Development, the Division of State Architect, the 
Office of the State Fire Marshal, tiie Office of Statewide Health Planning and Development, the California 
Energy Commission, and the Building Standards Commission (Commission). 

This collaborative effort included the assistance of the Commission's Code Advisory Committees and many 
other volunteers that worked tirelessly to assist the Corxmiission in the production of this Code. 

Members of the Building Standards Commission 
Secretary Rosario Marin^ - Chair Christina Jamison 

Isam Hasenin - Vice-Chair Stephen Jensen 

James Barthman Robert Pemell 

BCim Blackseth Richard Sawhill 

Susan Dowty Steven Winkel 

David Walls - Executive Director 

Thomas Morrison - Deputy 

Executive Director 



For questions on California state agency amendments; please refer to the contact list on the following page. 



IV 



2007 California Code of Regulations Title 24 

California Agency Information Contact List 



Cialifornia Energy Commission 

Energy Hotline (800) 772-3300 

Building Efficienq^ Standards 
Appliance Efficiency Standards 
Compliance Manual /Forms 

California State Lands Commission 

Marine Oil Terminals , (562) 499-6317 

California State Library 

Construction Standards (916) 445-9604 

Corrections Standards Authority 

Local Adult Jail Standards (916) 324-1914 

Local Juvenile Facility Standards . . .(916) 324-1914 

Department of Consumer Affairs - 
Acupuncture Board 

Office Standards (916) 445-3021 

Department of Consumer Affairs - 
Board of Pharmacy 

Pharmacy Standards .(916) 574-7900 

Department of Consumer Affairs - Bureau of 
Barbering and Cosmetology 

Barber and Beauty Shop and 

College Standards (916) 952-5210 

Department of Consumer Affairs - Bureau of 
Home Furnishings and Thermal Insulation 

Insulation Testing Standards (916) 574-2041 

Department of Consumer Affairs - 
Structural Pest Control Board 

Structural Standards (800) 737-8188 

Department of Consumer Affairs - 
Veterinary Medical Board 

Veterinary Hospital Standards ■. . . .(916) 263-2610 

Department of Food and Agriculture 

Meat & Poultry Packing Plant 

Standards (916) 654-0509 

Dairy Standards .(916) 654-0773 

Department of Health Services 

Organized Camps Standards (916) 449-5661 

Public Swimming Pools 

Standards .(916) 449-5661 

Asbestos Standards (510) 620-2874 



Department of Housing and Community 
Development 

Residential - Hotels, Motels, Apartments, 

Single-Family Dwellings .(916) 445-9471 

Permanent Structures in Mobilehome and 

Special Occupancy Parks (916) 445-9471 

Factory-Built Housing, Manufactured 

Housing and Commercial Modular .(916) 445-3338 

Mobile Homes - Permits & Inspections 

Northern Region (916) 255-2501 

Southern Region (951) 782-4420 

Employee Housing Standards (916) 445-9471 

Department of Water Resources 

Gray Water Installations Standards .(916) 651-9667 

Division of the State Architect - Access 
Compliance 

Access Compliance Standards (916) 445-8100 

Division of the State Architect - Structural 
Safety 

Public Schools Standards (916) 445-8100 

Essential Services Building 

Standards (916) 445-8100 

Division of the State Architect - State Historical 
Building Safety Board 

Alternative Building Standards (916) 445-8100 

Office of Statewide Health Planning and 
Development 

Hospital Standards (916) 654-3139 

Skilled Nursing Facility Standards .(916) 654-3139 

Clinic Standards (916) 654-3139 

Permits (916) 654-3362 

Office of the State Fire Marshal 

Code Development and Analysis . .(916) 445-8200 

Fire Safety Standards (916) 445-8200 

Fireplace Standards (916) 445-8200 

Day Care Centers Standards (916) 445-8200 

Exit Standards (916) 445-8200 



UMC FOREWORD 

Not Adopted by The State of California 



The Uniform Mechanical Codd^ (UMC®) provides complete requirements for the installation and mainte- 
nance of heating, ventilating, cooling, and refrigeration systems, while at the same time allowing latitude for 
innovation and new technologies. 

This code was first published in 1967. With the publication of the 2003 edition of the Uniform l\/leciianical 
Codd^, another significant milestone was reached. For the first time in the history of the United States, a 
mechanical code was developed through a true consensus process. The 2006 edition represents the most 
current approaches in the mechanical field and is the second edition developed under the ANSI Consensus 
process. Contributions to the content of this code were made by every segment of the built industry, includ- 
ing such diverse interests as consumers, enforcing authorities, installers/maintainers, insurance, labor, 
manufacturers, research/standards/testihg laboratories, special experts, and users. 

The public at large is encouraged and invited to participate in lAPMO's open consensus code development 
process. This code is updated every three years. A code development timeline and other relevant infor- 
mation is available at lAPMO's website at www.iapmo.org. 

The Uniform Mectianical Codd^ is dedicated to all those who, in working to achieve "the ultimate mechan- 
ical code," have unselfishly devoted their time, effort, and personal funds to create and maintain this, the 
finest mechanical code in existence today. 

The 2006 Uniform Mecl^anicai Cod^ is supported by the American Society of Sanitary Engineering (ASSE), 
Mechanical Contractors Association of America (MCAA), Plumblng-Heating-Cooling Contractors National 
Association (PHCC-NA), the United Association (UA), and the World Plumbing Council (WPC). The presence 
of these logos, while reflecting support, does not imply any ownership of the copyright to the UMC which is 
held exclusively by lAPMO. Further, the logos of these associations indicates the support of lAPMO's open, 
consensus process being used to develop lAPMO's codes and standards. 

The addresses of the organizations are as follows: 

ASSE - 901 Canterbury Road, Suite A • Westlake, Ohio 44145-7201 ' (440) 835-3040 
MCAA- 1385 Piccard Drive • Rockville, Maryland 20850 • (301) 869-5800 
PHCC-NA - PO Box 6808 • Falls Church, Virginia 22046 • (800) 533-7694 
UA - 901 Massachusetts Avenue NW • Washington, DC 20001 • (202) 628-5823 
WPC - WPC Secretary • c/o The Institute of Plumbing • 64 Station Lane • Hornchurch Essex 
RM12 6NB • United Kingdom • +44 17-08-47-27-91 



Code changes made to the original amalgamated code are marked in the 
margins as follows. 

■^— An arrow denotes a deletion | A vertical line dendtes a change 



VI 



TABLE OF CONTENTS 

California Mect^anicai Code Preface Hi 

California Building Standards Commission Contact List v 

UMC Foreword , : vi 

How to Distinguish Model Code Language from California Amendments ...viii 

Related Publications and Services ix 

California Matrix Adoption Tables ....xii 

Chapter 1 California General Code Provisions. ; 1 

Chapter 2 Definitions .....17 

Chapters General Requirements.,.. 31 

Chapter 4 Ventilation Air Supply 43 

Chapters Exhaust Systems 59 

Chapter 6 Duct Systems ....' ; 93 

Chapter 7 Combustion Air , 107 

Chapter 8 Chimneys and Vents Ill 

Chapter 9 Installation of Specific Equipment 147 

Chapter 10 Steam and Hot Water Boilers... 167 

Chapter 11 Refrigeration 175 

Chapter 12 Hydronics ., 191 

Chapter 13 Fuel Gas Piping 201 

Chapter 14 Process Piping .263 

Chapter 15 Solar Systems.. , ...267 

Chapter 16 Stationary Fuel Cell Power Plants r. 269 

Chapter 17 Standards '. ..271 

y4ppend/x Chapter 1 Administration 313 

Appendix A Uniform Mechanical Codes Standards 323 

Appendix B Procedures to be followed to place Gas Equipment in Operation 369 

Appendix C Installation and Testing of Oil (Liquid) Fuel-Fired Equipment 371 

Appendix D Unit Conversion Tables 379 

Index 385 

History. Note Appendix 395 



vn 



HOW TO DISTINGUISH MODEL CODE LANGUAGE 
FROM CALIFORNIA AMENDMENTS 



To distinguish between model code language and incorporated California amend- 
ments, including exclusive California standards California amendments will appear 
in italics. Symbols in the margins indicate the status of code changes as follows: 

[SFM] This symbol identifies which state agency(s) have amended a section of 
model code. For a complete listing of state agencies, refer to the Application 
Sections within Chapter 1. 

II This symbol indicates that a change has been made to a California amend- 

ment. 

*** This symbol indicates that model language has been deleted within a 
California amendment. 

^ This symbol indicates deletion of California language. 



VIII 



^ 



RELATED PUBLICATIONS AND SERVICES 

The Documents Listed are Not by this Reference Adopted by The State of California. 

lAPMO provides a variety of other products wiiich are useful for inspectors, building officials, architects, engineers, 
manufacturers, contractors, plumbers, and apprentices. 

lAPMO Headquarters Directory 

5001 East Philadeipiiia Street, Ontario, California 91761-2816 

Publication Order Desk Phone: 800-85-IAPMO 

Publication Toll Free Fax: 877-85-CODES 

E-mail: iapmo@iapmo.org 

Website: www.iapmo.org 

Free Code Question Answers & Analysis: 800-201-0335 

Uniform Mechanical Code - 2006 Edition: 

The Uniform Mechanical Code contains complete requirements for the installation and maintenance of 
heating, ventilating, cooking and refrigeration systems. 

Uniform iVIeclianicai Code iiiustrated Training l\flanuai: 

Contains technical diagrams and illustrations that demonstrate the intent and use of the UMC. A great 
reference for everyone involved in Mechanical HVACR design and installation. 

Uniform lUIechanical Code Study Guide: 

The Study Guide is a complete self-study course for learning the UMC. A big help in getting ready for 
a certification exam! This book is the perfect complement to the UMC Illustrated Training Manual. 

Cumulative Analysis of Uniform Mechanical Code Changes: 

The UMC Cumulative Analysis is a very useful tool in targeting the latest changes between editions of 
the code. It is an excellent guide for anyone proposing a UMC change. 

Uniform Plumbing Code - 2006 Edition: 

The Uniform Plumbing Code is the most widely adopted pltimbing code in the world. The 2006 edi- 
tion contains complete "turnkey" requirements for the installation and maintenance of plumbing sys- 
tems, all in one easy to use book. 

Uniform Plumbing Code Illustrated Training Manual: 

The UPC Illustrated Training Manual is an excellent reference for anyone involved in the plumbing 
industry. It contains an extensive definitions section and several hundred comprehensive technical dia- 
grams and illustrations. It serves as a textbook, and it also is useful as a valuable tool for explaining the 
intent and use of the Code. 

Uniform Plumbing Code Study Guide: 

This book is the perfect complement to the UPC Illustrated Training Manual. Alone, it constitutes a 
complete self-study course for learning the UPC. It has hundreds of questions, general practice exams, 
and plumbing matfi, pipe sizing exercises and fitting identification. A big help in gettiag you ready for 
a certification exam! 

Uniform Plumbing Code Answer & Analysis Manual: 

This increasing popular manual is the result of ongoing work by lAPMO's Answers & Analysis 
Committee. Updated annually, it contains htmdreds of questions and answers. Many of these questions 
arise in the daily administration o the code. 

Cumulative Analysis of Uniform Plumbing Code Changes: 

An excellent reference for learning and tinderstanding plumbing code changes adopted at the Aimual 
Education and Business Conferences. It is a useful tool for preparing code change proposals. 

ix 



RELATED PUBLICATIONS AND SERVICES 

The Documents Listed are Not by this Reference Adopted by The State of California. 



Uniform Plumbing Code - Spanishi Edition: 

The UPC Spanish Edition was translated in response to numerous requests from jurisdictions with 
large Spanish-speaking populations. 

Dwelling Requirements of the Uniform Plumbing Code: 

This book contains the UPC reqmrements that apply to one and two family dwellings only Its illustra- 
tions and photographs make it especially useful for combination dwelling inspectors and the do-it- 
yourselfer. 

Uniform Swimming Pool, Spa, and Hot Tub Code: 

Contains complete and current guidelines for piping systems serving these increasingly popular 
ameruties. 

Uniform Solar Energy Code: 

The Uniform Solar Energy Code is a tmique document that provides a complete set of regulations and 
guidelines that cover both plumbing and mechanical systems in one "turnkey" package. The code is 
ideal for use by inspectors, jurisdictions and the installation industry. 

Drain Waste and Vent Calculator: 

A slide-rule style calculator provides quick and simple access to the fixture unit and sizing tables of 
Chapter 7 of the UPC. 

Water Sizing Calculator: 

Sizing water systems becomes a much simpler task with the use of this handy slide-rule style calculator. 

Natural Gas Pipe Sizing Calculator: 

This Natural Gas Pipe Sizing Calculator is presented in an easy to use and read slide-rule format. 
Designed for systems with a supply presstire of six to eight inches of water column, all pipe capacities 
are given in cubic feet per hour. 

Trailer Standards: 

lAPMO has developed a number of standards for specialty products used in manufactured homes and 
recreational vehicles. These standards are available individually, or they may be purchased as a set. 

Directory of Listed Plumbing Products: 

The lAPMO Listing Program was primarily created to benefit the building and pltimbing officials that 
the products installed meet the appropriate standards and code. For a product to continue to be listed, 
tmarmounced inspections of the manufacturing facilities verify continued compliance. This directory 
contains information on several thousand lAPMO-Usted plumbing products and is updated annually. 

ICES-IAPIUIO Certification Evaluation Services: 

An independent, third party Certification system for jurisdictions to adopt and for individuals to take 
standardized, validated exams for over 100 different construction trade categories for Code 
Administrators, Inspectors, Plan Reviewers, Contractor and Journey level tradesmen, all based upon 
corrunonly utilized model codes. Custom certification and licensing exam creation to meet any juris- 
dictions special needs is available. 

Education and Training Seminars: 

lAPMO specializes in conducting training and education, including fulfilling continuing education 
requirements, on the UPC and UMC as well as all of the most commonly utilized codes in the Construc- 
tion Trades. Special seminars on industry or code subjects are expeditiously created and delivered upon 
request. Please call to obtain the seminar schedule or to arrange for a custom special seminar. 



RELATED PUBLICATIONS AND SERVICES 

The Documents Listed are Not by this Reference Adopted by The State of California. 



Backflow Prevention Institute - lAPIVIO 

The lAPMO Backflow Prevention Institute provides professional education and training for the control 
of hazards to our water supply and is dedicated to water-system safety worldwide. The Institute pro- 
vides training in backflow prevention and cross-connection control. This program includes backflow 
preventers, testers, repairers, and cross-connection control surveyors. Each of these courses provides 
compliance certification to American National Standards Institute standards. 

Bacl<flow Prevention Reference IVlanuai: 

This unique 300-page manual contains full-color illustrations and sections relating to real-world instal- 
lations, backflow prevention, testing cross-connection control, repair and inspections. The manual is an 
excellent textbook and a reference Ae raspectors in every jurisdiction should have access too. It is also 
an important resource for system designers, urban planners and utility companies - professionals on 
both sides of the water meter. 

Drinl<ing Water & Bac[(flow Prevention IVIagazine: 

A monthly subscription to Drinking Water & Backflow Prevention Magazine provides current and 
valuable information regarding this critical public health topic. Subjects range from actual incident 
reporting, application of the newest technology, and general interest articles including fire systems, irri- 
gation systems, and security as well as installation, inspection and repair tips. 

Backflow Prevention Tecii-Whieel: 

Find quick answers to your backflow questions! The Backflow Tech- Wheel contains a wealth of ii\for- 
mation in a graphic, quick reference format. One side delivers solutions to device application questions; 
the other a troubleshooting guide offering solutions to backflow problems. 

ANSI Z 124 Standards: 

These standards are written to specifically address a variety of plastic plumbing fixtures and compo- 
nents. They are available individually, or may be grouped for quantity discounts. 

IAPI\/IO Installation Standards: 

lAPMO standards committees have formulated installation standards for a wide variety of commorUy 
used plumbiag materials and systems. The lAPMO installation standards are included after the text of 
the Uniform Plumbing Code, or can be purchased separately. 

Material and Property Standards: 

lAPMO does not generally develop material and property standards, but when a need exists the 
Association will take a leadership role by filling the void. They are available, are subject to amendments 
and are withdrawn when recognized consensus standards are formulated. 

OFFICIAL Magazine: 

lAPMO's bimonthly publication features informative articles related to plumbing and Mechanical 
HVACR installations, award winning general interest features, technical columns and industry 
updates. Subscriptions are available and all lAPMO members receive a free copy of every issue! 

Membersliip In lAPMO: 

lAPMO membership is open to all interested persons. Membership categories iiiclude Student, 
Individual, Corporate and Jurisdictional. Member benefits include discotmted prices on most LAPMO 
publications, a subscription to Official magazine, and numerous educational and training opportunities. 

HOW TO CONTACT lAPMO 

Mailing Address: 5001 East Philadelphia Stireet, Ontario, California 91761-2816 

Main Number: 909-472-4100 • Publication Orders: 800-85-IAPMO • Publication Fax: 877-85-CODES 

Website: www.iapmo.org • Office Hours: Monday - Friday, 8am - 5pm Pacific Time 

xi 



MATRIX ADOPTION TABLES 2007 CALIFORNIA MECHANICAL CODE 

CALIFORNIA MATRIX ADOPTION TABLES 



Format of the Matrix Adoption Tables 

The matrix adoption tables, which follow, show the user which state agencies have adopt- 
ed and /or amended given sections of model code for applications within their respective 
authorities. See Chapter 1, See Sections 102 through 114, for building application and 
enforcement responsibilities. 

The side headings identify the scope of the state agencies' adoption as follows: 

Adopt the Entire UPC Chapter without state amendments 

If there is an "X" xmder a particular state agency's acronym on this row, this means that partic- 
lilar state agency has adopted the entire model code chapter without any state amendments. 

Example: 




Adopt the Entire UPC chapter as amended (amendments listed below) 

If there is an "X" xmder a particular state agency's acronym on this row, it means that partic- 
ular state agency has adopted the entire model code chapter, with state amendments. 

Each state-amended section that the agency has added to that particular chapter is listed. 
There will be an "X" in the column, by that particular section, xxnder the agency's acronym, as well 
as an "X" by each section that the agency has adopted. 



Example: 



CHAPTER 1 - GENERAL CODE PROVISIONS 



Adopting Agency 



Adopt Entire Chapter 




Adopt Entire Chapter as 
annended (amended 
sections listed below) 



Adopt only those sections 
that are listed below 



XII 



2007 CALIFORNIA MECHANICAL CODE 



MATRIX ADOPTION TABLES 



Adopts only those section which are listed below: 

If there is an "X" under a particular state agency's acronym on this row, it means that particu- 
lar state agency is adopting only specific model code or state-amended sections within this chap- 
ter. There will be an "X" in the column under the agency's acronym, as well as an "X" by each sec- 
tion that the agency has adopted. 



Example: 



CHAPTER 1 ■ GENERAL CODE PROVIS 



Adopting Agency 



Adopt Entire Chapter 



Adopt Entire Chapter as 
amended (amended 
sections iisted beiow) 



Adopt only those sections 
that are listed below 



Article / Section 



101 



102 



Codes 




Legend of Abbreviations of Adopting State Agencies 

BSC California Building Standards Commission 

SFM Office of the State Fire Marshal 

HCD Department of Housing and Community Development 

DSA-AC Division of the State Architect - Access Compliance 

DSA - SS Division of the State Architect - Structural Safety 

OSHPD Office of Statewide Health Planning and Development 

CA Department of Consumer Affairs 

DHS Department of Health Services 



XIII 



MATRIX ADOPTION TABLES 



2007 CALIFORNIA MECHANICAL CODE 



CALIFORNIA CHAPT 


ER1 


■ GENERAL CODE 


PR( 


)VIS 


ION 


3 






Adopting Agency 


BSC 


SFM 


HCD 1 


DSA 


OSHPD 1 


CA 


DHS 


1 


2 


AC 


ss 


1 


2 


3 


4 






Adopt Entire Chapter 


























Adopt Entire Chapter as amended 
(amended sections listed below) 


























Adopt only those sections that are 
listed below 


X 


X 


X 


X 


X 


X 


X 


X 


X 


X 


X 


X 


Article/Section 


Codes 




101 


CA 


X 


X 


X 


X 




X 


X 


X 


X 


X 


X 


X 


102 


CA 


X 
























104 


CA 






















X 




107 


CA 
























X 


108 


CA 






X 


X 


















109.1 


CA 










X 
















109.2 


CA 












X 














110.1 


CA 














X 












110.2 


CA 
















X 










110.3 


CA 


















X 








110.4 


CA 




















X 






111 


CA 




X 






















CHAPTER 2- DEFIN 


TIONS 


Adopting Agency 


BSC 


SFM 


HCD 


DSA 


OSHPD 


CA 


DHS 




1 


2 


AC 


ss 


1 


2 


3 


4 








Adopt Entire Chapter 


X 










X 
















Adopt Entire Chapter as amended 
(amended sections listed below) 




X 


X 


X 






X 


X 


X 


X 








Adopt only those sections that are 
listed below 




























Article/Section 


Codes 




203 


CA 




X 


X 


X 






X 


X 


X 


X 








204 


CA 




X 


X 


X 






X 


X 


X 


X 








206 


CA 






X 


X 




















207 


CA 




X 


X 


X 






X 


X 


X 


X 








208 


CA 




X 


X 


X 




















210 


CA 














X 


X 


X 


X 








214 


CA 




X 


X 


X 




















215 


CA 




X 
























216 


CA 






X 


X 




















217 


CA 




X 


X 


X 






X 


X 


X 


X 








218 


CA 






X 


X 




















221 


CA 














X 


X 


X 


X 








222 


CA 






X 


X 




















223 


CA 




X 


X 


X 






X 


X 


X 


X 









XIV 



2007 CALIFORNIA MECHANICAL CODE 



MATRIX ADOPTION TABLES 









CHAPTER 3- 


-GENE 


RAL REQUIREMENTS 
















Adopting Agency 


BSC 


SFM 


HCD 


DBA 


OSHPD 


CA 


DHS 


1 


2 


AC 


as 


1 


2 


3 


4 






Adopt Entire Chapter 


X 










X 














Adopt Entire Ciiapter as amended 
(amended sections listed below) 




X 


X 


X 






X 


X 


X 


X 






Adopt only tliose sections that are 
listed below 


























Article/Section 


Codes 


304.2 Exc. 2 


CA 














X 


X 




X 






304.6 


CA 




X 






















304.7 


CA 






X 


X 


















313.0 


CA 














X 


X 




X 






314.1 


CA 














X 






X 






314.2 


CA 
















X 




X 






315.1 


. CA 














X 






X 






315.2 . 


CA 
















X 




X 






315.3 


CA 


















X 








316.0 


CA 














X 


X 


X 


X 






Tab|e.315 


■ CA 














X 


X 


X 


X 




, 




CHAPTER 4 - VENTILATION AIR SUPPLY 




Adopting Agency 


BSC 


SFM 


■ HCD 


DBA 


OSHPD 


CA 


DHS 






1 


2 


AC 


ss 


1 


2 


3 


4 










Adopt Entire Chapter 






X 


X 




X 


















Adopt Entire Chapter as amended 
(amended sections listed below) 


X 


X 


























Adopt only those sections that are 
listed below 














X 


X 


X 


X 










Article/Section 


Codes 






401.0 


CA 




X 










X 


X 


X 


X 










402.0 


■ CA 














X 


X 


X 


X 










402.1 


■ CA 


X 












X 


X 


X 


X 










404.0 


UMC 














X 


X 


X 


X 










405.0 


CA 














X 


X 


X 


X 










407.0 


CA 














X 


X 


X 


X 










408.0 


CA 














X 


X 


X 


X 










409.0 


CA 














X 


X 


X 


X 










410.0 


. CA 














X 


X 


X 


X 










411.0 


CA 














X 


X 


X 


X 










412.0 


CA 














X 


X 


X 


X 










413.0 


CA 














X 


X 


X 


X 










414.0 . 


CA 














X 


X 


X 


X 










415.0 


CA 














X 


X 


X 


X 










416.0 


CA 














X 


X 


X 


X 










416.3 . 


CA 














X 


X 


X 


X 










417.0 


CA 














X 


X 


X 


X 










418.0 • 


■ , CA 














X 


X 


X 


X 










Table 4-1, Note 


CA 


X 




























Table 4-A; 


CA 














X 


X 


X 


X 










Table 4-B 


CA 














X 




X 












Table 4-C 


CA 
















X 




X 









XV 



MATRIX ADOPTION TABLES 



2007 CALIFORNIA MECHANICAL CODE 





CHAPTEF 


1 5- EXHAUST SYSTEMS 












Adopting Agency 


BSC 


SFM 


HOD 


DSA 


OSHPD 


CA 


DHS 


1 


2 


AC 


SS 


1 


2 


3 


4 






Adopt Entire Ctiapter 


X 




X 


X 




X 














Adopt Entire Ctiapter as amended 
(amended sections iisted below) 




X^ 










X 


X 


X 


X 




X 


Adopt only tliose sections that are 
listed below 






















X 




Article/Section 


Codes 


504.1 


CA 














X 






X 






505.12 


CA 






















X 




505.12.1 


CA 






















X 




508.1.1 


CA 














X 


X 




X 






509.2.4 


CA 




X 






















509.2.4.4 


CA 
























X 


510.7.1 


UIMC 




t 






















510,7,1.1 


CA 




X 






















513,2.2 


CA 




X 






















513.2.2.1 


UIVIC 


























513.10 


CA 




X 






















513.10.1 


CA 




X 






















513.10.2 


CA 




X 























1 . This state agency adopts the entire chapter as amended except for those sections indicated by the following symbol: 





CHART 


ER6- 


DUCT SYSTEMS 














Adopting Agency 


BSC 


SFM 


HCD 


DSA 


OSHPD 


CA 


DHS 


1 


2 


AC 


ss 


1 


2 


3 


4 






Adopt Entire Chapter 


X 










X 














Adopt Entire Chapter as amended 
(amended sections listed below) 




X 


X 


X 






X 


X 


X 


X 






Adopt only those sections that are 
listed below 


























Article/Section 


Codes, 


601.2 


CA 






X 


X 


















602.1 Exc. 


CA 














X 


X 


X 


X 






602.3.1 


CA 














X 


X 


X 


X 






605.0 


CA 














X 


X 


X 


X 






605.1 


CA 














X 


X 


X 


X 






605.2 


CA 














X 


X 




X 






606.8 


CA 




X 






















607.1.1 


CA, 














X 


X 


X 


X 






609.0 


CA 




X 























XVI 



2007 CALIFORNIA MECHANICAL CODE 



MATRIX ADOPTION TABLES 





CHAPTER 7- ( 


COMBUSTION AIR 












Adopting Agency 


BSC 


SFM 


HOD 


DSA 


OSHPD 


CA 


DHS 


1 


2 


AC 


SS 


1 


2 


3 


4 






Adopt Entire Chapter 


X 


X 


X 


X 




X 


X 


X 


X 


X 




X 


Adopt Entire Chapter as amended 
(amended sections listed below) 


























Adopt only those sections that are 
listed beiow 


























Article/Section 


Codes 

































CHA 


PTER 


B-CH 


MNEYS AND VE 


NTS 












Adopting Agency 


BSC 


SFM 


HOD 


DSA 


OSHPD 


CA 


DHS 


1 


2 


AG 


SS 


1 


2 


3 


4 






Adopt Entire Chapter 


X 


X 


X 


X 




X 


X 


X 


X 


X 






Adopt Entire Chapter as amended 
(amended sections listed below) 


























Adopt only those sections that are 
listed below 


























Article/Section 


Codes 






























Article/Section 


Codes 























































CHAPTER 9- 


INSTALLATION OF SPECIFIC EQUIPMENT 






Adopting Agency 


BSC 


SFM 


HCD 


DSA . 


OSHPD 


CA 


DHS 


1 


2 


AC 


SS 


1 


2 


3 


4 






Adopt Entire Chapter 


X 










X 






X 








Adopt Entire Chapter as amended 
(amended sections listed below) 




X 


X 


X 






X 


X 




X 






Adopt only those sections that are 
listed below ■ 
























X 


Article/Section 


Codes 


. 902.0(D) 


CA 














X 


X 




X 






907.0 


UMC 
























X 


907.1 


CA 














X 


X 




X 






924.1 


CA 






X 


X 


















924.1.1 


CA 






X 


X 


















932,0 


CA 




X 


X 


X 


















932.1 


CA 




X 


X 


X 


















932.2 


CA 




X 


X 


X 


















932.3 


CA 




X 


X 


X 


















932.4 


CA 




X 


X 


X 


















932.5 


CA 




X 


X 


X 



















XVII 



MATRIX ADOPTION TABLES 



2007 CALIFORNIA MECHANICAL CODE 





CHAPTER 1 


0- STEAM AND H01 


r WATER BOILERS 








Adopting Agency 


BSC 


SFM 


HOD 


DSA 


OSHPD 


CA 


DHS 


1 


2 


AC 


SS 


1 


2 


3 


4 






Adopt Entire Ciiapter 


X 


X 


X 


X 




X 


X 


X 


X 


X 




X 


Adopt Entire Chapter as amended 
(amended sections listed below) 


























Adopt only those sections that are 
listed below 


























Article/Section 


Codes 

































CHAPTER 11- 


REFRIGERATIO 


N 












Adopting Agency 


BSC 


SFM 


HCD 


DSA 


OSHPD 


CA 


DHS 


1 


2 


AC 


SS 


1 


2 


3 


4 






Adopt Entire Chapter 


X 


X 


X 


X 




X 












X 


Adopt Entire Chapter as amended 
(amended sections listed below) 














X 


X 


X 


X 






Adopt only those sections that are 
listed below 


























Article/Section 


Codes 


1131.1 


CA 














X 


X 


X 


X 






Table 11-1 


CA 














X 


X 




X 






Table 11-2 


CA 














X 


X 


X 


X 











CHAP 


TER12-H 


YDF 


(ONICS 














Adopting Agency 


BSC 


SFM 


HCD 


DSA 


OSHPD 


CA 


DHS 


1 


2 


AC 


SS 


1 


2 


3 


4 






Adopt Entire Chapter 


X 




X 


X 




X 


X 


X 


X 


X 






Adopt Entire Chapter as amended 
(amended sections listed below) 


























Adopt only those sections that are 
listed below 


























Article/Section 


Codes 

































CH 


APTE 


R13- 


FUEL GAS PIPING 












Adopting Agency 


BSC 


SFM 


HCD 


DSA 


OSHPD 


CA 


DHS 


1 


2 


AC 


SS 


1 


2 


3 


4 






Adopt Entire Chapter 


X 


X 








X 


X 


X 


X 


X 






Adopt Entire Chapter as amended 
(amended sections listed below) 


























Adopt only those sections that are 
listed below 


























Article/Section 


Codes 































XVIll 



2007 CALIFORNIA MECHANICAL CODE 



MATRIX ADOPTION TABLES 





CHAPTER 14- 


PROCESS PIPING 












Adopting Agency 


BSC 


SFM 


HOD 


DSA 


OSHPD 


CA 


DHS 


1 


2 


AC 


SS 


1 


2 


3 


4 






Adopt Entire Cfiapter 


X 


X 








X 


X 


X 


X 


X 






Adopt Entire Ctiapter as amended 
(amended sections listed below) , 


























Adopt only those sections ttiat are 
listed below 


























Article/Section 


Codes 






























CHAPTE 


R 15 -SOLAR SYSTEMS 


Adopting Agency 


BSC 


SFM 


HOD 


DSA 


■ OSHPD 


CA . 


DHS 


1 


2 


AC 


SS 


1 


2 


3 


4 






Adopt Entire Chapter 












X 














Adopt Entire Chapter as amended 
(amended sections listed below) 


























Adopt only those sections that are 
listed below 






X 


X 


















Article/Section • 


Codes 


1500 • 


CA 






X 


X 



















CHAPTER 16- 


STAT! 


ONAR 


YFL 


lEL 


CELL PC 


IWEI 


^PL 


ANT 


s 






Adopting Agency 


BSC 


SFM 


HCD 


DSA 


OSHPD 


CA 


DHS 


1 


2 


AC 


SS 


1 


2 


3 


4 






Adopt Entire Chapter 


X 


X 


X 


X 




X 














Adopt Entire Chapter as amended 
(amended sections listed below) 


























Adopt only those sections that are 
listed below 


























Article/Section 


Codes 



































CHAP" 


FERI? 


'-S 


TAN 


DARDS 














Adopting Agency 


BSC 


SFM 


HCD , 


DSA 


OSHPD 


CA 


"DHS 


1 


2 


AC 


SS 


1 


2 


3 


4 






Adopt Entire Chapter 


X 


X 


X 


X 




X 


X 


X 


X 


X 






Adopt Entire Chapter as amended 
(amended sections listed below) 


























Adopt only those sections that are 
listed below 


























Article/Section 


Codes 































XIX 



MATRIX ADOPTION TABLES 



2007 CALIFORNIA MECHANICAL CODE 





APPENDIX CHAPTER i- 


-ADMINISTRATION 










Adopting Agency 


BSC 


SFM 


HOD 


DSA 


OSHPD 


CA 


DHS 


1 


2 


AC 


SS 


1 


2 


3 


4 






Adopt Entire Chapter 


























Adopt Entire Chapter as amended 
(amended sections listed below) 














X 


X 


X 


X 






Adopt only those sections that are 
listed below 






X 


X 


















Article/Section 


Codes 


103.0 


CA 














X 


X 


X 


X 






112.2-112.2.5 


UMC 






X 


X 





















APPENDIX A 


- UMC STANDARDS NOS. 2-2, 6-2, & 6-5 








Adopting Agency 


BSC 


SFM 


HOD 


DSA 


OSHPD 


CA 


DHS 


1 


2 


AC 


SS 


1 


2 


3 


4 






Adopt Entire Chapter 


X 


X 


X 


X 




X 


X 


X 


X 


X 






Adopt Entire Chapter as amended 
(amended sections listed below) 


























Adopt only those sections that are 
listed below 
























X 


Article/Section 


Codes 


UMC Std. No. 6-2 


UiVIC 
























X 



APPENDIX B-PR( 
E 


)CEDl 
QUIPW 


IRES1 
lENTI 


■0 BE FOLLOWE 
NTO OPERATION 


DTC 


)PL 


ACE 


GAJ 


3 




Adopting Agency 


BSC 


SFM 


HCD 


DSA 


OSHPD 


CA 


DHS 


1 


2 


AC 


ss 


1 


2 


3 


4 






Adopt Entire Chapter 


X 












X 


X 


X 


X 






Adopt Entire Chapter as amended 
(amended sections listed below) 


























Adopt only those sections that are 
listed below 


























Article/Section Codes 



APPENDIX C- IK 


STALI 
FUEL 


-ATIOI 
.-FIRE 


^ AND TESTING OF OIL (LIQUID) 
D EQUIPMENT 






Adopting Agency 


BSC 


SFM 


HCD 


DSA 


OSHPD 


CA 


DHS 


1 


2 


AC 


SS 


1 


2 


3 


4 






Adopt Entire Chapter 


X 












X 


X 


X 


X 






Adopt Entire Chapter as amended 
(amended sections listed below) 


























Adopt only those sections that are 
listed below 


























Article/Section Codes 



XX 



2007 CALIFORNIA MECHANICAL CODE 



MATRIX ADOPTION TABLES 



APPENDIX D- 


- UNIT CONVERSION TABLES 










Adopting Agency 


BSC 


SFM 


HCD 


DSA 


OSHPD 


CA 


DHS 


1 


2 


AC 


SS 


1 


2 


3 


4 






Adopt Entire Chapter 


X 




X 


X 




X 


X 


X 


X 


X 






Adopt Entire Chapter as amended 
(amended sections listed below) 


























Adopt only those sections that are 
listed below 


























Article/Section Codes 



XXI 



MATRIX ADOPTION TABLES 2007 CALIFORNIA MECHANICAL CODE 



XXil 



CALIFORNIA CHAPTER 1 

GENERAL CODE PROVISIONS 



101.0 General. 

101.1 Title. These regulations shall be known as the 
California Mechanical Code, may be cited as such and will 
be referred to herein as "this code." The California 
Mechanical Code is Part 4 of twelve parts of the official 
compilation and publication of the adoptions, amendment, 
and repeal of mechanical regulations to the California Code 
of Regulations, Title 24, also referred to as the California 
Building Standards Code. This part incorporates by 
adoption the 2006 Uniform Mechanical Code of the 
International Association of Plumbing and Mechanical 
Officials with necessary California amendments. 

101.2 Purpose, The purpose of this code is to establish 
the minimum requirements to safeguard the public health, 
safety and general welfare through structural strength, 
means of egress facilities, stability, access to persons with 
disabilities, sanitation, adequate lighting and ventilation, 
and energy conservation; to preserve life and property 
from fire and other hazards attributed to the built 
environment; and to provide safety to fire fighters and 
emergency responders during emergency operations. 

101.3 Scope. The provisions of this code shall apply to 
the construction, alteration, movement, enlargement, 
replacement, repair, equipment, use and occupancy, 
location, maintenance, removal and demolition of every 
building or structure or any appurtenances connected or 
attached to such building structures throughout the State 
of California. 

101.3.1 Non-State-Regulated Buildings, 
Structures, and Applications. Except as modified 
by local ordinance pursuant to Section 101.8, the 
building standards in the California- Code of 
Regulations, Title 24, Parts 2, 3, 4, 5, 6, 9 and 10 
shall apply to all occupancies and applications not 
regulated by a state agency. 

101.3.2 State-Regulated Buildings, Structures, 
and Applications. The model code, state amendments 
to the model code, and/or state amendments where there 
are no relevant model code provisions, shall apply to the 
following buildings structures, structures, and 
applications regulated by state agencies as referenced in 
the Matrix Adoption Tables and as specified in Sections 
102 through 114, except where modified by local 
ordinance pursuant to Section 101.8. When adopted by 
a state agency, the provisions of this code shall be 
enforced by the appropriate enforcing agency, but only 
to. the extent of authority granted to such agency by the 
State Legislature. 

Note: See the Preface to distinguish the model code 
provisions from the California provisions. 



(1) State-owned buildings, including buildings 
constructed by the Trustees of the California 
State University, and to the extent permitted by 
California laws, buildings designed and 
constructed by the Regents of the University of 
California, and regulated by the Building 
Standards Commission. See Section 102 for 
additional scope provisions. 

(2) Reserved for Corrections Standards Authority. 
See section 103 for additional scope provisions. 

(3) Barbering, cosmetology or electrolysis 
establishments, establishment, acupuncture 
offices, pharmacies, veterinary facilities, and 
structural pest control locations regulated by the 
Department of Consumer Affairs. See Section 
104 for additional scope provisions. 

(4) Reserved for the California Energy Commission. 
See Section 105 for additional scope provisions. 

(5) Reserved for the Department of Food and 
Agriculture. See Section 106 for additional scope 
provisions. 

(6) Organized camps, laboratory animal quarters, 
public swimming pools, radiation protection, 
commissaries serving mobile food preparation 
vehicles, and wild animal quarantine facilities 
regulated by the Department of Health Services. 
See Section 107 for additional scope provisions. 

(7) Hotels, motels, lodging houses, apartment 
houses, dwellings, dormitories, condominiums, 
shelters for homeless persons, congregate 
residences, employee housing, factory-built 
housing, and other types of dwellings containing 
sleeping accommodations with common toilets or 
cooking facilities. See Section 108 for additional 
scope provisions. 

(8) Accommodations for persons with disabilities in 
buildings containing newly constructed covered 
multifamily dwellings, new common use spaces 
serving existing covered multifamily dwellings, 
additions to existing buildings where the 
addition alone meets the definition of a covered 
multifamily dwelling, and common-use spaces 
serving covered multifamily dwellings which are 
regulated by Department of Housing and 
Community Development. See Section 108 for 
additional scope provisions. . 

(9) Permanent buildings and permanent accessory 
buildings or structures constructed within 



101.3-101.7 



2007 CALIFORNIA MECHANICAL CODE 



mobilehome parks and special occupancy parks 
regulated by the Department of Housing and 
Community Development. See Section 108 for 
additional scope provisions. 

(10) Accommodations for persons with disabilities 
regulated by the Division of the State Architect. 
See Section 109.1 for additional scope provisions. 

(11) Public elementary and secondary schools, 
community college buildings, and state-owned or 
state-leased essential service buildings regulated 
by the Division of the State Architect. See 
Section 109.3 for additional scope provisions. 

(12) Reserved for the State Historical Building Safety 
Board with the Division of the State Architect. 
See Section 109.3 for additional scope provisions. 

(13) General acute care hospitals, acute psychiatric 
hospitals, skilled nursing and/or intermediate 
care facilities, clinics licensed by the Department 
of Health Services, and correctional treatment 
centers regulated by the Office of Statewide 
Health Planning and Development. See Section 
no for additional scope provisions. 

(14) Applications regulated by the Office of State Fire 
Marshal include but are not limited to the 
following in accordance with Section 111: 

1. Buildings or structures used or 
intended for use as an: 

1.1 Asylum, jail 

1.2 Mental hospital, hospital, home for the 
elderly, children's nursery, children's 
home or institution, school or any similar 
occupancy of any capacity 

1.3 Theater, dancehall, skating rink, auditorium, 
assembly hall, meeting hall, nightclub, fair 
building, or similar place of assemblage 
where 50 or more persons may gather 
together in a building, room or structure 
for the purpose of amusement, entertainment, 
instruction, deliberation, worship, drinking 
or dining, awaiting transportation, or 
education 

1.4 Small family day care homes, large family 
day-care homes, residential facilities and 
residential facilities for the elderly, residential 
care facilities 

1.5 State institutions or other state-owned or 
state-occupied buildings 

1.6 High rise structures 

1.7 Motion picture production studios 

1.8 Organized camps 

1.9 Residential structures 



2. Tents, awnings or other fabric enclosures 
used in connection with any occupancy 

3. Tire alarm devices, equipment and systems in 
connection with any occupancy 

4. Hazardous materials, flammable and 
combustible liquids 

5. Public school automatic fire detection, alarm, 
and sprinkler systems 

6. Wildland urban interface fire areas 

(15) Reserved for the State Librarian. See Section 112 
for additional scope provisions. 

(16) Reserved for the Department of Water Resources. 
See Section 113 for additional scope provisions. 

(17) Reserved for the State Lands Commission. See 
Section 114 for additional scope provisions. 

101.4 Appendices. Provisions contained in the 
appendices of this code shall not apply unless specifically 
adopted by a state agency or adopted by a local enforcing 
agency in compliance with Health and Safety Code 
Section 18938(b) for Building Standards Law, Health and 
Safety Code 17950 for State Housing Law and Health and 
Safety Code Section 13869.7 for Fire Protection Districts. 
See Section 101.8 of this code. 

101.5 Referenced Codes. The codes, standards and 
publications adopted and set forth in this code, including 
other codes, standards and publications referred to therein 
are, by title and date of publication, hereby adopted as 
standard reference documents of this code. When this code 
does not specifically cover any subject related to building 
design and construction, recognized architectural or 
engineering practices shall be employed. The National Fire 
Codes and the Fire Protection Handbook of the National 
Fire Protection Association are permitted to be used as 
authoritative guides in determining recognized fire- 
prevention engineering practices. 

101.6 Non-Building Standards, Orders and 
Regulations. Requirements contained in the Uniform 
Mechanical Code, or in any other referenced standard, 
code or document, which are not building standards as 
defined in Section 18909, Health and Safety Code, shall 
not be construed as part of the provisions of this code. For 
non-building standards, orders, and regulations, see other 
titles of the California Code of Regulations. 

101.7 Order of Precedence and Use. 

101.7.1 Differences. In the event of any differences 
between these building standards and the standard 
reference documents, the text of these building 
standards shall govern. 

101.7.2 Specific Provision. Where a specific 
provision varies from a general provision, the specific 
provisions shall apply. 



ADMINISTRATION 



101.7-102.1 



101.7.3 Conflicts. When the requirements of this 
code conflict with the requirements of any other part 
of the California Building Standards Code, Title 24, 
the most restrictive requirement shall prevail. 

101.8 City, County, or City and County Amendments, 
Addition or Deletions. The provisions of this code do 
not limit the authority of city, county, or city and county 
governments to establish more restrictive and reasonably 
necessary differences to the provisions contained in this 
code pursuant to complying with section 101.8.1. The 
effective date of amendments, additions, or deletions to 
this code of cities, counties, or city and counties filed 
pursuant to section 101.8.1 shall be the date filed. 
However, in no case shall the amendments, additions or 
deletions to this code be effective any sooner than the 
effective date of this code. 

101.8.1 Findings and Filings. 

(1) The city, county, or city and county shall make 
express findings for each amendment, addition or 
deletion based upon climactic, topographical, or 
geological conditions. 

Exception: Hazardous building ordinances and 
programs mitigating unreinforced masonry 
buildings. 

(2) The city, county, or city and county shall file the 
amendments, additions, or deletions expressly 
marked and identified as to the applicable 
findings. Cities, counties, cities and counties, 
and fire departments shall file the amendments, 
additions or deletions, and the findings with the 
California Building Standards Commission at 
2525 Natomas Park Drive, Suite 130, 
Sacramento, CA 95833. 

(3) Findings prepared by fire protection districts 
shall be ratified by the local city, county, or city 
and county and filed with the California 
Department of Housing and Community 
Development at 1800 3rd Street, Room 260, 
Sacramento, CA 95814. 

101.9 Effective Date of this Code. Only those 
standards approved by the California Building Standards 
Commission that are effective at the time an application for 
building permit is submitted shall apply to the plans and 
specifications for, and to the construction performed under, 
that permit. Tor the effective dates, of the provisions 
contained in this code, see the History Note page of this code. 

101.10 Availability of Codes. At least one copy of each 
of Titles 8, 19, 20, 24 and 25 with all revisions shall be 
maintained in the office of the building official responsible 
for the administration and enforcement of this code. See 
Health and Safety Code Section 18942 (d)(1) & (2). 

101.11 Format. This part fundamentally adopts the 
Uniform Mechanical Code by reference on a chapter-by- 



chapter basis. Such adoption is reflected in the Matrix 
Adoption Table of each chapter of this part. When the 
Matrix Adoption Tables make no reference to a specific 
chapter of the Uniform Mechanical Code, such chapter of 
the Uniform Mechanical Code is not adopted as a portion 
of this code. 

101.12 Validity. If any chapter, section, subsection, 
sentence, clause or phrase of this code is for any reason 
held to be unconstitutional, contrary to statute, exceeding 
the authority of the state as stipulated by statutes, or 
otherwise inoperative, such decision shall not affect the 
validity of the remaining portion of this code. 

102.0 Building Standards Commission. 

102.1 Specific scope of application of the agency 
responsible for enforcement, the enforcement agency, and 
the specific authority to adopt and enforce such provisions 
of this code, unless otherwise stated. 

1. State Buildings tor all occupancies. 

Application — State buildings (all occupancies), 
including buildings constructed by the Trustees 
of the California State University and the 
Regents of the University of California where no 
state agency has the authority to adopt building 
standards applicable to such buildings. 

Enforcing Agency - State or local agency 
specified by the applicable provisions of law. 

Authority Cited - Health and Safety Code 
section 18934.5. 

Reference - Health and Safety Code, Division 
13, Part 2.5, commencing with section 18901. 

2. University of California, California 
State Universities, and California 
Community Colleges. 

Application - Standards for lighting for parking 
lots and primary campus walkways at the 
University of California, California State 
Universities, and California Community Colleges. 

Enforcing Agency - State or local agency 
specified by the applicable provisions of law. 

Authority Cited - Government Code section 
14617. 

Reference - Government Code section 14617. 

3. Existing State-Owned Buildings, 
Including those owned by the University 
of California and by the California State 
University 

Application - Building seismic retrofit 
standards including abating falling hazards of 
structural and nonstructural components and 
strengthening of building structures. See also 
Division of the State Architect. 



108.1 -108.2 



2007 CALIFORNIA MECHANICAL CODE 



Enforcing Agency - State or local agency 
specified by the applicable provisions of law. 

Authority Cited - Government Code section 
16600 

Reference - Government Code sections 16600 
through 16604 

4. Unreinforced Masonry Bearing Wall 
Buildings. 

Application - Minimum seismic strengthening 
standards for buildings specified in Appendix 
Chapter 1 of the California Code for Building 
Conservation, except for buildings subject to 
building standards adopted pursuant to Part 1.5 
(commencing with Section 17910) 

Enforcing Agency - State or local agency 
specified by the applicable provisions of law. 

Authority Cited - Health and Safety Code 
section 18934.6 

Reference - Health and Safety Code sections 
18901 through 18949 

103.0 Reserved for Corrections Standards Autiiority. 

104.0 Department of Consumer Affairs. 

104.1 Specific scope of application of the agency 
responsible for enforcement, the enforcement agency, and 
the specific authority to adopt and enforce such provisions 
of this code, unless otherwise stated. 

Board of Pharmacy. 

Application - Pharmacies. 

Enforcing Agency - State or local agency specified by 
applicable provisions of law. 

Authority Cited - Business and Professions Code section 
4005. 

Reference - Business and Professions Code section 4005, 
4127.7 and 4201. 

105.0 Reserved for California Energy Commission. 

106.0 Reserved for Department of Food and 
Agriculture. 

107.0 Department of Health Services. 

107.1 Specific scope of application of the agency 
responsible for enforcement, the enforcement agency, and 
the specific authority to adopt and enforce such provisions 
of this code, unless otherwise stated. 

Department of Health Services. 

Application - Pood establishments 



Enforcing Agency - Department of Health Services and 
the local health agency 

Authority Cited - Health and Safety Code sections 
100275,110065 and 113710 

Reference - Health and Safety Code sections 100275, 
110065, 113705 and 114140 

108.0 Department of Housing and Community 
Development (HCD) 

108.1 Purpose. The purpose of this code is to establish 
minimum standards to protect, the health, safety, and 
general welfare of the occupant and the public by 
governing the erection, construction, enlargement, 
conversion, alteration, repair, moving, removal, 
demolition, ventilation and maintenance or use of heating, 
ventilating, cooling refrigeration systems, incinerators 
and other miscellaneous heat-producing appliances. 

108.2 Authority and Abbreviations 

108.2.1 General. The Department of Housing and 
Community Development is authorized by law to 
promulgate and adopt building standards and 
regulations for several types of building applications. 
These applications are grouped and identified by 
abbreviation in the Matrix Adoption Tables to show 
which model code sections and amendments are 
applicable to each application. The applications 
under the authority of the Department of Housing 
and Community Development are listed in Sections 
108.2.1.1 through 108.2.1.3. 

108.2.1.1 Housing Construction. 

Application - Hotels, motels, lodging houses, 
apartment houses, dwellings, dormitories, 
condominiums, shelters for homeless persons, 
congregate residences, employee housing, 
factory-built housing and other types of 
dwellings containing sleeping accommodations 
with or without common toilet or cooking 
facilities including accessory buildings, facilities, 
and uses thereto. Sections of this code which 
pertain to applications listed in this section are 
identified in the Matrix Adoption Table using 
the abbreviation "HCD 1". 

Enforcing Agency: Local building department 
or the Department of Housing and Community 
Development. 

Authority Cited: Health and Safety Code 
Sections 17921, 17922, 19990 through 19992; 
and Government Code Section 12955.1. 

Reference: Health and Safety Code Sections 
17000 through 17062.5, 17910 through 17995.5, 
18200 through 18700, 18860 through 18874, 
and 19960 through 19997; and Government 
Code Section 12955.1. 



ADMINISTRATION 



108.2-108.3 



108.2.1.2 Housing Accessibility. 

Application- Covered multifamily dwelling 
units as defined in Chapter 11 A of the California 
Code of Regulations, Title 24, Part 2, also known 
as the California Building Code (CBC) including, 
but not limited to, lodging houses, dormitories, 
time-shares, condominiums, shelters for homeless 
persons, congregate residences, apartment houses, 
dwellings, employee housing, factory-built 
housing and other types of dwellings containing 
sleeping accommodations with or without 
common toilet or cooking facilities. 

Sections of this code identified in the Matrix 
Adoption Table by the abbreviation "HCD 
II AC" require specific accommodations for 
persons with physical disabilities, as defined in 
Chapter 11 A of the CBC. The application of such 
provisions shall be in conjunction with other 
requirements of this code and apply only to 
Group R Occupancies which are newly- 
constructed covered multifamily dwellings as 
defined in Chapter llA of the CBC. "HCD 
1/AC" applications include, but are not limited 
to, the following: 

(1) All newly-constructed covered multifamily 
dwellings as defined in Chapter 11 A of the 
CBC. 

(2) New common use areas as defined in Chapter 
11 A of the CBC serving existing covered 
multifamily dwellings. 

(3) Additions to existing buildings, where the 
addition alone meets the definition of a 
covered multifamily dwelling as defined in 
Chapter UA of the CBC. 

(4) Common use areas serving covered multi- 
family dwellings. 

HCD lA/C building standards generally do not 
apply to public use areas or public accommo- 
dations such as hotels and motels. Public use 
areas, public accommodations, and housing 
which is publicly funded as defined in Chapter 2, 
Chapter llA, and Chapter IIB of the CBC, are 
subject to the Division of the State Architect 
(DSA/AC) and are referenced in Section 109.1. 

Enforcing Agency: Local building department 
or the Department of Housing and Community 
Development. 

Authority Cited: Health and Safety Code 
Sections 17921, 17922, 19990 through 19992; 
and Government Code Section 12955.1. 

Reference: Health and Safety Code Sections 
17000 through 17062.5, 17910 through 17995.5, 
18200 through 18700, 18860 through 18874, 



and 19960 through 19997; and Government 
Code Section 12955.1. 

108.2.1.3 Permanent Buildings In Mobile- 
home Parks and Special Occupancy Parks. 

Application - Permanent buildings, and 
permanent accessory buildings or structures, 
constructed within mobilehome parks and special 
occupancy parks that are under the control and 
ownership of the park operator. Sections of this 
code which pertain to applications listed in this 
section are identified in the Matrix Adoption 
Table using the abbreviation "HCD 2". 

Enforcing Agency: Local building department 
or other local agency responsible for the 
enforcement of Health and Safety Code Division 
13, Part 2.1 and Part 2.3, commencing with 
Sections 18200 and 18860 respectively, or the 
Department of Housing and Community 
Development. 

Authority Cited: Health and Safety Code 
Sections 17921, 17922, 18300 and 18865. 

Reference: Health and Safety Code Sections 
17000 through 17062.5, 17910 through 17995.5, 
18200 through 18700, 18860 through 18874, 
and 19960 through 19997; and Government 
Code Section 12955.1. 

108.3 Local Enforcing Agency 

108.3.1 Duties and Powers. The building 
department of every city, county or city and county 
shall enforce all the provisions of law, this code, and 
the other rules and regulations promulgated by the 
Department of Housing and Community 
Development pertaining to the installation, erection, 
construction, reconstruction, movement, enlargement, 
conversion, alteration, repair, removal, demolition, or 
arrangement of apartment houses, hotels, motels, 
lodging houses and dwellings, including accessory 
buildings, facilities, and uses thereto. 

The provisions regulating the erection and 
construction of dwellings and appurtenant structures 
shall not apply to existing structures as to which 
construction is commenced or approved prior to the 
effective date of these regulations. Requirements 
relating to use, maintenance and occupancy shall 
apply to all dwellings and appurtenant structures 
approved for construction or constructed before or 
after the effective date of this code. 

For additional information regarding the use and 
occupancy of existing buildings and appurtenant 
structures, see California Code of Regulations, Title 
25, Division 1, Chapter 1, Subsection 1, Article 1, 
commencing with Section 1. 

108.3.2 Laws, Rules, and Regulations. Other 
than the building standards contained in this code. 



108.3-108.4 



2007 CALIFORNIA MECHANICAL CODE 



and notwithstanding other provisions of law, the 
statutory authority and location of the laws, rules, 
and regulations to he enforced by local enforcing 
agencies are listed by statute in Sections 108.3.2.1 
through 108.3.2.5 below: 

108.3.2.1 State Housing Law. Refer to the 
State Housing Law, California Health and Safety 
Code, Division 13, Part 1.5 commencing with 
Section 17910, and California Code of 
Regulations, Title 25, Division 1, Chapter 1, 
Subchapter 1, Article 1, commencing with Section 
1, for the erection, construction, reconstruction, 
movement, enlargement, conversion, alteration, 
repair, removal, demolition, or arrangement of 
apartment houses, hotels, motels, lodging houses 
and dwellings, including accessory buildings, 
facilities, and uses thereto. 

108.3.2.2 Mobilehome Parks Act. Refer to 
the Mobilehome Parks Act, California Health 
and Safety Code, Division 13, Part 2.1, 
commencing with Section 18200 and California 
Code of Regulations, Title 25, Division 1, 
Chapter 2, Article 1, commencing with Section 
1000 for mobilehome park administrative and 
enforcement authority, permits, plans, fees, 
violations, inspections and penalties both within 
and outside mobilehome parks. 

Exception: Mobilehome parks where the 
Department of Housing and Community 
Development is the enforcing agency. 

108.3.2.3 Special Occupancy Parlis Act. 

Refer to the Special Occupancy Parks Act, 
California Health and Safety Code, Division 13, 
Part 2.3, commencing with Section 18860 and 
California Code of Regulations, Title 25, 
Division 1, Chapter 2.2, Article 1, commencing 
with Section 2000 for special occupancy park 
administrative and enforcement authority, 
permits, fees, violations, inspections and 
penalties both within and outside of special 
occupancy parks. 

Exception: Special occupancy parks where the 
Department of Housing and Community 
Development is the enforcing agency. 

108.3.2.4 Empioyee Housing Act. Refer to 
the Employee Housing Act, California Health and 
Safety Code, Division 13, Part 1, commencing 
with Section 17000 and California Code of 
Regulations, Title 25, Division 1, Chapter 1, 
Subchapter 3, Article 1, commencing with Section 
600 for employee housing administrative and 
enforcement authority, permits, fees, violations, 
inspections and penalties. 



108.3.2.5 Factory-Built Housing. Refer to the 
Factory-Built Housing Law, California Health 
and Safety Code, Division 13, Part 6, commencing 
with Section 19960 and California Code of 
Regulations, Title 25, Division 1, Chapter 3, 
Subchapter 1, Article 1, commencing with Section 
3000 for factory-built housing administrative and 
enforcement authority, permits, fees, violations, 
inspections and penalties. 

108.4 Permits, Fees, Applications, and Inspections 

108.4. 1 Permits. A written construction permit shall 
be obtained from the enforcing agency prior to the 
erection, construction, reconstruction, installation, 
relocation, or alteration of any mechanical system. 

Exceptions: 

(1) Work exempt from permits as specified in 
Appendix Chapter 1, Sections 112.2 through 
112.2.5 of this code. 

(2) Changes, alterations, or repairs of a minor 
nature not affecting structural features, egress, 
sanitation, safety or accessibility as determined 
by the enforcing agency. 

Exemptions from permit requirements shall not be 
deemed to grant authorization for any work to be 
done in any manner in violation of other provisions of 
law or this code. 

108.4.2 Fees. Subject to other provisions of law, 
the governing body of any city, county, or city and 
county may prescribe fees to defray the cost of 
enforcement of rules and regulations promulgated by 
the Department of Housing and Community 
Development. The amount of the fees shall not exceed 
the amount reasonably necessary to administer or 
process permits, certificates, forms, or other 
documents, or to defray the costs of enforcement. For 
additional information, see State Housing Law, 
Health and Safety Code, Division 13, Part 1.5, 
Section 17951 and California Code of Regulations, 
Title 25, Division 1, Chapter 1, Subchapter 1, Article 
3, commencing with Section 6. 

108.4.3 Plan Review and Time Limitations. 

Subject to other provisions of law, provisions related 
to plan checking, prohibition of excessive delays, and 
contracting with or employment of private parties to 
perform plan checking are set forth in State Housing 
Law, Health and Safety Code Section 17960.1, and 
for employee housing, in Health and Safety Code 
Section 17021. 

108.4.3.1 Retention of Plans. The building 
department of every city, county or city and 
county shall maintain an official copy, 
microfilm, or electronic or other type of 
photographic copy of the plans of every building. 



ADMINISTRATION 



108.4-108.6 



during the life of the building, for which the 
department issued a building permit. 

Exceptions: 

(1) Single or multiple dwellings not more than two 
stories and basement in height. 

(2) Garages and other structures appurtenant to 
buildings listed in exception (1). 

(3) Farm or ranch buildings appurtenant to 
buildings listed in exception (1). 

(4) Any one-story building where the span between 
bearing walls does not exceed 25 feet, except a 
steel frame or concrete building. 

All plans for common interest developments as 
defined in Section 1351 of the California Civil 
Code shall be retained. For additional 
information regarding plan retention and 
reproduction of plans by an enforcing agency, 
see Health and Safety Code Sections 19850 
through 19852. 

108.4.4 Inspections. Construction or work for 
which a permit is required shall be subject to inspection 
by the building official and such construction or work 
shall remain accessible and exposed for inspection 
purposes until approved. Approval as a result of an 
inspection shall not be construed to be an approval of a 
violation of the provisions of this code or other 
regulations of the Department of Housing and 
Community Development. 

108.5 Right of Entry for Enforcement 

108.5.1 Generai. Subject to other provisions of law, 
officers and agents of the enforcing agency may enter 
and inspect public and private properties to secure 
compliance with the rules and regulations 
promulgated by the Department of Housing and 
Community Development. For limitations and 
additional information regarding enforcement, see the 
following: 

■ (1) For applications subject to State Housing Law as 
referenced in Section 108.3.2.1 of this code, refer 
to Health and Safety Code Sections 17970 
through 17972 and California Code of Regulations, 
Title 25, Division 1, Chapter 1, Subchapter 1. 

(2) For applications subject to the Mobilehome Parks 
Act as referenced in Section 108.3.2.2 of this 
code, refer to the Health and Safety Code, 
commencing with Section 18200, and California 
Code of Regulations, Title 25, Division 1, Chapter 2. 

(3) For applications subject to the Special 
Occupancy Parks Act as referenced in Section 
108.3.2.3 of this code, refer to the Health and 
Safety Code, commencing with Section 18860, 
and California Code of Regulations, Title 25, 
Division 1, Chapter 2.2. 



(4) For applications subject to the Employee 
Housing Act as referenced in Section 108.3.2.4 
of this code, refer to Health and Safety Code 
Section 17052 and California Code of 
Regulations, Title 25, Division 1, Chapter 1, 
Subchapter 3. 

(5) For applications subject to the Factory-Built 
Housing Act as referenced in Section 108.3.2.5 
of this code, refer to Health and Safety Code 
Sections 19991 through 19992 and California 
Code of Regulations, Title 25, Division 1, 
Chapter 3, Subchapter 1. 

108.6 Locai Modification by Ordinance or 
Regulation 

108.6.1 General. Subject to other provisions of 
law, a city, county or city and county may make 
changes to the provisions adopted by the Department 
of Housing and Community Development. If any 
city, county or city and county does not amend, add, 
or repeal by local ordinances or regulations the 
provisions published in this code or other regulations 
promulgated by the Department of Housing and 
Community Development, those provisions shall be 
applicable and shall become effective 180 days after 
publication by the California Building Standards 
Commission. Amendments, additions, and deletions 
to this code adopted by a city, county or city and 
county pursuant to California Health and Safety 
Code Sections 17958.7 and 18941.5, together with all 
applicable portions of this code, shall also become 
effective 180 days after publication of the California 
Building Standards Code by the California Building 
Standards Commission. 

108.6.2 Findings, Filings, and Rejections of 
Local Modifications. Prior to making any 
modifications or establishing more restrictive 
building standards, the governing body shall make 
express findings and filings, as required by California 
Health and Safety Code Section 17958.7 stating their 
findings and that such modifications are reasonably 
necessary due to local climatic, geological, or 
topographical conditions. No modification shall 
become effective or operative unless the following 
requirements are met: 

(1) The express findings shall be made available as a 
public record. 

(2) A copy of the modification and express finding, 
each document marked to cross-reference the 
other, shall be filed luith the California Building 
Standards Commission for cities, counties, or 
cites and counties, and with the Department of 
Housing and Community Development for fire 
protection districts. 



108.6-108.8 



2007 CALIFORNIA MECHANICAL CODE 



(3) The California Building Standards Commission 
has not rejected the modification or change. 

Nothing in this section shall limit the authority of fire 
protection districts pursuant to California Health and 
Safety Code Section 13869.7 (a). 

108.7 Alternate Materials, Designs, Tests and 
Methods of Construction 

108.7.1 General. The provisions of this code as 
adopted by the Department of Housing and 
Community Development are not intended to 
prevent the use of any alternate material, appliance, 
installation, device, arrangement, design or method of 
construction not specifically prescribed by this code. 
Consideration and approval of alternates shall comply 
with Section 108.7.2 for local building departments 
and Section 108.7.3 for the Department of Housing 
and Community Development. 

108.7.2 Local Building Departments. The 

building department of any city, county or city and 
county may approve alternates for use in the erection, 
construction, reconstruction, movement enlargement, 
conversion, alteration, repair, removal demolition or 
arrangement of apartment houses, hotels, motels, 
lodging houses, dwellings, including accessory 
buildings, facilities, and uses thereto , except for the 
following: 

(1) Structures located in mobilehome parks as 
defined in California Health and Safety Code 
Section 18214. 

(2) Structures located in special occupancy parks as 
defined in California Health and Safety Code 
Section 18862.43. 

(3) Factory-built housing as defined in California 
Health and Safety Code Section 19971. 

108.7.2.1 Approval of Alternates. The 

consideration and approval of alternates by a 
local building department shall comply with the 
following procedures and limitations: 

(1) The approval shall be granted on a case-by- 
case basis. 

(2) Evidence shall be submitted to substantiate 
claims that the proposed alternate, in 
performance, safety, and for the protection 
of life and health, conforms to, or is at least 
equivalent to, the standards contained in 
this code and other rules and regulations 
promulgated by the Department of Housing 
and Community Development. 

(3) The local building department may require 
tests performed by an approved testing 
agency at the expense of the owner or owner's 
agent as proof of compliance. 

(4) If the proposed alternate is related to 



accessibility in covered multifamily dwellings 
or facilities serving covered multifamily 
dwellings as defined in Chapter 11 A of the 
CBC, the proposed alternate must also meet 
the threshold set for "EQUIVALENT FACILI- 
TATION" as defined in Chapter llA of the CBC. 

For additional information regarding approval of 
alternates by a local building department 
pursuant to the State Housing Law, see 
California Health and Safety Code Section 
17951(e) and California Code Regulations, Title 
25, Division 1, Chapter 1, Subchapter 1. 

108.7.3 Department of Housing and 
Community Development. The Department of 
Housing and Community Development may approve 
alternates for use in the erection, construction, 
reconstruction movement, enlargement, conversion, 
alteration, repair, removal or demolition of an 
apartment house, hotel, motel, lodging house, 
dwelling, or an accessory thereto. The consideration 
and approval of alternates shall comply with the 
following: 

(1) The Department may require tests at the expense 
of the owner or owner's agent to substantiate 
compliance with the California Building 
Standards Code. 

(2) The approved alternate shall, for its intended 
purpose, be at least equivalent in performance 
and safety to the materials, designs, tests, or 
methods of construction prescribed by this code. 

108.8 Appeals Board 

108.8. 1 General. Every city, county or city and 
county, shall establish a local appeals board and a 
housing appeals board. The local appeals board and 
housing appeals board shall each be comprised of at 
least five voting members who shall serve at the 
pleasure of the city, county or city and county. 
Appointees shall not be employees of the jurisdiction 
and shall be qualified and specifically knowledgeable 
in the California Building Standards Codes and 
applicable local ordinances. 

108.8.2 Definitions. The following terms shall for 
the purposes of this section have the meaning shown. 

Housing Appeals Board. The board or agency of a 
city, county or city and county which is authorized 
by the governing body of the city, county or city and 
county to hear appeals regarding the requirements of 
the city, county or city and county relating to the use, 
maintenance, and change of occupancy of buildings 
and structures, including requirements governing 
alteration, additions, repair, demolition, and moving. 
In any area in which there is no such board or agency, 
"housing appeals board" means the local appeals 
board having jurisdiction over the area. 



ADMINISTRATION 



108.8-108.10 



Local Appeals Board. The board or agency of a 
city, county or city and county which is authorized 
by the governing body of the city, county or city and 
county to hear appeals regarding the building 
requirements of the city, county or city and county. 
In any area in which there is no such board or agency, 
"local appeals board" means the governing body of 
the city, county or city and county having 
jurisdiction over the area. 

108.8.3 Appeals. Except as otherwise provided by 
law, any person, firm, or corporation adversely 
affected by a decision, order, or determination by a 
city, county or city and county relating to the 
application of building standards published in the 
California Building Standards Code, or any other 
applicable rule or regulation adopted by the 
Department of Housing and Community 
Development, or any lawfully enacted ordinance by a 
city, county or city and county, may appeal the issue 
for resolution to the local appeals board or housing 
appeals board as appropriate. 

The local appeals board shall hear appeals relating to 
new building construction and the housing appeals 
board shall hear appeals relating to existing buildings. 

108.9 Unsafe Buildings or Structures 

108.9.1 Authority to Enforce. Subject to other 
provisions of law, the administration, enforcement, 
actions, proceedings, abatement, violations and 
penalties for unsafe buildings and structures are 
contained in the following statutes and regulations: 

(1) For applications subject to State Housing Law as 
referenced in Section 108.3.2.1 of this code, refer 
to Health and Safety Code Sections 17910 
through 17995.5 and California Code of 
Regulations, Title 25, Division 1, Chapter 1, 
Subchapter 1. 

(2) For applications subject to the Mobilehome Parks 
Act as referenced in Section 108.3.2.2 of this 
code, refer to the Health and Safety Code, 
commencing with Section 18200 and California 
Code of Regulations, Title 25, Division 1, 
Chapter 2. 

(3) For applications subject to the Special Occupancy 
Parks Act as referenced in Section 108.3.2,3 of 
this code, refer to the Health and Safety Code, 
commencing with Section 18860 and California 
Code of Regulations, Title 25, Division 1, 
Chapter 2.2. 

(4) For applications subject to the Employee Housing 
Act as referenced in Section 108.3.2.4 of this 
code, refer to Health and Safety Code Sections 
17000 through 17062.5 and California Code of 
Regulations, Title 25, Division 1, Chapter 1, 
Subchapter 3. 



(5) For applications subject to the Factory-Built 
Housing Act as referenced in Section 108.3.2.5 
of this code, refer to Health and Safety Code 
Sections 19960 through 19997 and California 
Code of Regulations, Title 25, Division 1, 
Chapter 3, Subchapter 1. 

108.9.2 Actions and Proceedings. Subject to 
other provisions of law, punishments, penalties and 
fines for violations of building standards are 
contained in the following statutes and regulations: 

(1) For applications subject to State Housing Law as 
referenced in Section 108.3.2.1 of this code, refer 
to Health and Safety Code Sections 17980 
through 17995.5 and California Code of 
Regulations, Title 25, Division 1, Chapter 1, 
Subchapter 1. 

(2) For applications subject to the Mobilehome Parks 
Act as referenced in Section 108.3.2.2 of this 
code, refer to Health and Safety Code Sections 
18200 through 18700 and California Code of 
Regulations, Title 25 Division 1, Chapter 2. 

(3) For applications subject to the Special 
Occupancy Parks Act as referenced in Section 
108.3.2.3 of this code, refer to Health and Safety 
Code Sections 18866 through 18869 and 
California Code of Regulations, Title 25, 
Division 1, Chapter 2.2. 

(4) For applications subject to the Employee 
Housing Act as referenced in Section 108.3.2.4 
of this code, refer to Health and Safety Code 
Sections 17000 through 17062.5 and California 
Code of Regulations, Title 25, Division 1, 
Chapter 1, Subchapter 3. 

(5) For applications subject to the Factory-Built 
Housing Act as referenced in Section 108.3.2.5 
of this code, refer to Health and Safety Code 
Sections 19995 through 19997 and California 
Code of Regulations, Title 25, Division 1, 
Chapter 3, Subchapter 1. 

108.10 Oilier Building Regulations 

108.10.1 Existing Structures. Notwithstanding 
other provisions of law, the replacement, retention, 
and extension of original materials and the use of 
original methods of construction for any existing 
building or accessory structure, or portions thereof, 
shall be permitted. For additional information, see 
California Health and Safety Code, Sections 17912 
and 17958.8. 

108.10.2 Moved Structures. Subject to the 
requirements of California Health and Safety Code 
Sections 17922.3 and 17958.9, local ordinances or 
regulations relating to a moved residential building 
or accessory structure thereto, shall, after July 1, 

' 1978, permit the retention of existing materials and 



108.10-110.3 



2007 CALIFORNIA MECHANICAL CODE 



methods of construction so long as the structure does 
not become or continue to be a substandard building. 

109.0 Division of thie State Arcfiitect 

109. 1 Division of ttie State Architect-Access 
Compliance. 

Note: For applications listed in Section 109.1 of the 
California Building Code, regulated by the Division of the 
State Architect-Access Compliance see California Code of 
Regulations, Title 24, Part 2 (California Building Code), 
California Chapter 1 (General Code Provisions) under 
authority cited by Government Code Section 4450 and in 
reference cited by Government Code Sections 4450 
through 4461, 12955.1 and Health and Safety Code 
Sections 18949.1, 19952 through 19959. 

109.2 Division of ttie State Arcfiitect - Structural 
Safety 

Application - Public elementary and secondary schools, 
community college buildings, and state-owned or state- 
leased essential services buildings. 

Enforcing Agency - (DSA - SS) 

Authority Cited - Education Code § 17310 and 81142, 
and H&S Code §16022. 

Reference - Education Code §§ 17280 through 17317, 
and 81130 through 81147, and H&S Code §§16000 
through 16023. 

The Division of the State Architect has been delegated the 
responsibility and authority by the Department of General 
Services to review and approve the design and observe the 
construction of public school buildings, and state-owned 
or state-leased essential services buildings. 

110.0 Office of Statewide Health Planning and 
Development 

110.1 OSHPD 1. Specific scope of application of the 
agency responsible for enforcement, enforcement agency, 
specific authority to adopt and enforce such provisions of 
this code, unless otherwise stated. 

OSHPD 1 

Application - General acute-care hospitals and acute 
psychiatric hospitals, excluding distinct part units or 
distinct part freestanding buildings providing skilled 
nursing or intermediate-care services. For Structural 
Regulations: Skilled nursing facilities and/or 
intermediate-care facilities except those skilled nursing 
facilities and intermediate care facilities of single story. 
Type V, wood or light steel-frame construction. 

Enforcing Agency -Office of Statewide Health Planning 
and Development (OSHPD). The office shall enforce the 
Division of the State Architect-Access Compliance 
regulations and the regulations of the Office of the State 
Fire Marshal for the above stated facility types. 



110.1.1 Applicable administrative standards. 

1. Title 24, Part 1, California Code of Regulations: 
Chapters 6&7. 

2. Title 24, Part 2, California Code of Regulations: 
Sections 101 and 110 of Chapter 1 and Appendix 
Chapter 1. 

110.1.2 Appiicabie building standards. 

California Building Standards Code, Title 24, Parts 
2, 3, 4, 5, 9, 10 and 12. 

NOTATION 

Authority: Health and Safety Code Sectionsl27010, 
127015, 1275 and 129850. 

Reference: Health and Safety Code Sections 
19958,127010, 127015, 129680, 1275 and 129675 
through 130070. 

1 10.2 OSHPD 2. Specific scope of application of the 
agency responsible for enforcement, enforcement agency, 
specific authority to adopt and enforce such provisions of 
this code, unless otherwise stated. 

OSHPD 2 

Application - Skilled nursing facilities and intermediate- 
care facilities, including distinct part skilled nursing and 
intermediate-care services on a general acute-care or acute 
psychiatric hospital license, provided either in a separate 
unit or a freestanding building. For Structural 
Regulations: Single-story, Type V skilled nursing facility 
and/or intermediate-care facilities utilizing wood or light 
steel-frame construction. 

Enforcing Agency - Office of Statewide Health Planning 
and Development (OSHPD). The office shall also enforce 
the Division of the State Architect-Access Compliance 
regulations and the regulations of the Office of the State 
Fire Marshal for the above stated facility type. 

1 10.2. 1 Appiicabie administrative standards: 

1. Title 24, Part 1, California Code of Regulations: 
Chapter 7. 

2. Title 24, Part 2, California Code of Regulations: 
Sections 101 and 110 of Chapter 1 and Appendix 
Chapter 1. 

110.2.2 Applicable building standards. 
California Building Standards Code, Title 24, Parts 
2, 3, 4, 5, 9, 10 and 12. 

NOTATION 

Authority: Health and Safety Code Sections 127010, 
127015, 1275 and 129850. 

References: Health and Safety Code Sections 
127010, 127015, 1275 and 129680. 

1 10.3 OSHPD 3. Specific scope of application of the 
agency responsible for enforcement, enforcement agency, 
specific authority to adopt and enforce such provisions of 
this code, unless otherwise stated. 



10 



ADMINISTRATION 



110.3-111.1 



OSHPD 3 

Application - Licensed clinics and any freestanding 
building under a hospital license where outpatient clinical 
services are provided. 

Enforcing Agency - Local building department. 

110.3.1 Applicable administrative standards. 

1. Title 24, Parti, California Code of Regulations: 
Chapter 7. 

2. Title 24, Part 2, California Code of Regulations: 
Sections 101 and 110 of Chapter 1 and Appendix 
Chapter 1. 

110.3.2 Applicable building standards. 

California Building Standards Code, Title 24, Parts 
2, 3, 4, 5, 9, 10 and 12. 

NOTATION 

Authority: Health and Safety Code Sections 
127010, 127015 and 1226. 

References: Health and Safety Code Sections 
127010, 127015,129885 and 1226, Government Code 
Section 54350, and State Constitution Article 11 
Section 7. 

110.4 OSHPD 4, Specific scope of application of the 

agency responsible for enforcement, enforcement agency, 

specific authority to adopt and enforce such provisions of 

this code, unless otherwise stated. 

OSHPD 4 

Application - Correctional Treatment Centers. 

Enforcing Agency - Office of Statewide Health Planning 
and Development (OSHPD). The Office shall also enforce 
the Division of the State Architect-Access Compliance 
regulations and the regulations of the Office of the State 
Tire Marshal for the above stated facility types. 

110.4. 1 Applicable administrative standards. 

1. Title 24, Part 1, California Code of Regulations: 
Chapter 7. 

2. Title 24, Part 2, California Code of Regulations: 
Sections 101 and 110 of Chapter 1 and Appendix 
Chapter 1. 

110.4.2 Applicable building standards. 

California Building Standards Code, Title 24, Parts 
2, 3, 4, 5, 9, 10 and 12. 

NOTATION 

Authority: Health and Safety Code Sections 
127010, 127015 and 129790. 

References: Health and Safety Code Sections 
■ 127010, 127015, 1275 and 129675 through 130070. 



home for the aged, children's nursery, children's home, 
school or any similar occupancy of any capacity. 

Any theater, dancehall, skating rink, auditorium, 
assembly hall, meeting hall, nightclub, fair building, or 
similar place of assemblage where 50 or more persons may 
gather together in a building, room or structure for the 
purpose of amusement, entertainment, instruction, 
deliberation, worship, drinking or diriing, awaiting 
transportation, or education. 

Authority Cited. Health and Safety Code Section 13143. 

Reference. Health and Safety Code Section 13143. 

Small Family Day-care Homes 

Authority Cited. Health and Safety Code Sections 
1597.45, 1597.54, 13143 and 17921. 

Reference. Health and Safety Code Section 13143. 

Large Family Day-care Homes 

Autiiority Cited. Health and Safety Code Sections 
1597.46, 1597.54 and 17921. 

Reference. Health and Safety Code Section 13143. 

Residential Facilities and Residential Facilities 
for the Elderly 

Authority Cited. Health and Safety Code Section 13133. 

Reference. Health and Safety Code Section 13143. 

Any state institution or other state-owned or 
state-occupied building. 

Authority Cited. Health and Safety Code Section 13108. 

Reference. Health and Safety Code Section 13143. 

High-rise Structures 

Authority Cited. Health and Safety Code Section 13211. 
Reference. Health and Safety Code Section 13143. 

n/lotion Picture Production Studios 

Authority Cited. Health and Safety Code Section 
13143.1. 

Reference. Health and Safety Code Section 13143. 

Organized Camps 

Authority Cited. Health and. Safety Code Section 
18897.3. 

Reference. Health and Safety Code Section 13143. 



111.0 Office of the State Fire IVIarshal 

111.1 SFI\/l-Office of the State Fire Marshal. 

' Any building or structure used or intended for use as 
an asylum, jail, mental hospital, hospital, sanitarium. 



Residential 

^ All hotels, motels, lodging houses, apartment houses 
and dwellings, including congregate residences and 
buildings' and structures accessory thereto. 



11 



111.1-111.2 



2007 CALIFORNIA MECHANICAL CODE 



Multiple-story structures existing on January 1, 
1975, let for human habitation, including and limited to, 
hotels, motels, apartment houses, less than 75 feet (22 860 
mm) above the lowest floor level having building access, 
wherein rooms used for sleeping are let above the ground 
floor. 

Authority Cited. Health and Safety Code Sections 

13143.2 and 17921. 

Reference. Health and Safety Code Section 13143. 

Residential Care Faciiities 

Certified family-care homes, out-of-home placement 
facilities, halfway houses, drug and/or alcohol 
rehabilitation facilities and any building or structure used 
or intended for use as a home or institution for the 
housing of any person of any age when such person is 
referred to or placed within such home or institution for 
protective social care and supervision services by any 
governmental agency. 

Authority Cited. Health and Safety Code Section 
13143.6. 

Tents, awnings or ottier fattric enciosures used 
in connection withi any occupancy. 

Authority Cited. Health and Safety Code Section 13116. 

Reference. Health and Safety Code Section 13143. 

Enforcing Agency. Pursuant to Section 13146, Health 
and Safety Code: 

Fire aiarm devices, equipment and systems in 
connection witti any occupancy. 

Authority Cited. Health and Safety Code Section 13114. 

Hazardous materials. 

Authority Cited. Health and Safety Code Section 
13143.9. 

Flammable and combustible liquids. 

Authority Cited. Health and Safety Code Section 
13143.6. 

Public School Automatic Fire Detection, Alarm, 
and Sprinkler Systems 

Authority Cited. Health & Safety Code Section 13143 
and California Education Code Article 7.5, Sections 
17074.50, 17074.52, & 17074.54. 

Reference. Government Code Section 11152.5 and Health 
& Safety Code Section 13143 and California Education 
Code Chapter 12.5, Leroy F.' Greene School Facilities Act 
of 1998, Article 1. 



Wildland Urban Interface Fire Area 

Authority Cited. Health & Safety Code Sections 13143, 
13108.5(a) and 18949.2(b) and (c) and Government Code 
Section 51189. 

Reference. Health & Safety Code Sections 13143and 
Government Code Sections 51176, 51177, 51178 and 
51179 and Public Resources Code Sections 4201 through 
4204 

1 1 1.2 Duties and Powers of the Enforcing Agency 
111.2.1 Enforcement. 

111.2.1.1 The responsibility for enforcement of 
building standards adopted by the State Fire 
Marshal and published in the California 
Building Standards Code relating to fire and 
panic safety and other regulations of the Office of 
the State Fire Marshal shall be as follows: 

1. The city, county, or city and county with 
jurisdiction in the area affected by the 
standard or regulation shall delegate the 
enforcement of the building standards 
relating to fire and panic safety and other 
regulations of the State Fire Marshal as they 
relate to Group R, Division 3 dwellings, as 
described in Section 310.1 of Part 2 of the 
California Building Standards Code, to 
either of the following: 

1.1. The chief of the fire authority of the city, 
county, or city and county, or an 
authorized representative. 

1.2. The chief building official of the city, 
county, or city and county, or an 
authorized representative. 

2. The chief of any city or county fire 
department or of any fife protection district, 
and authorized representatives, shall enforce 
within the jurisdiction the building 
standards and other regulations of the State 
Fire Marshal, except those described in Item 
lor 4. 

3. The State Fire Marshal shall have authority 

to enforce the building standards and other 
regulations of the State Fire Marshal in 
areas outside of corporate cities and districts 
providing fire protection services. 

4. The State Fire Marshal shall have authority 

to enforce the building standards and other 
regulations of the State Fire Marshal in 
corporate cities and districts providing fire- 
protection services on request of the chief 
fire official or the governing body. 

5. Any fee charged pursuant to the enforcement 

authority of this section shall not exceed the 
estimated reasonable cost of providing the 



12 



ADMINISTRATION 



111.2 



service for which the fee is charged pursuant 
to Section 66014 of the Government Code. 

111.2.1.2 Pursuant to Health and Safety Code 
Section 13108, upon the written request of the 
chief fire official of any city, county or fire- 
protection district, the State Fire Marshal may 
authorize such chief fire official and his or her 
authorized representatives, in their geographical 
area of responsibility, to make fire-prevention 
inspections of state-owned or state-occupied 
buildings, other than state institutions, for the 
purpose of enforcing the regulations relating to 
fire and panic safety adopted by the State Fire 
Marshal pursuant to this section and building 
standards relating to fire and panic safety 
published in the California Building Standards 
Code. Authorization from the State Fire Marshal 
shall be limited to those fire departments or fire 
districts which maintain a fire-prevention 
bureau staffed by paid personnel. 

Pursuant to Health and Safety Code 
Section 13108, any requirement or order made 
by any chief fire official who is authorized by the 
State Fire Marshal to make fire-prevention 
inspections of state-owned or state-occupied 
buildings, other than state institutions, may be 
appealed to the State Fire Marshal. The State 
Fire Marshal shall, upon receiving an appeal and 
subject to the provisions of Chapter 5 
(commencing with Section 18945) of Part 2, 5 of 
Division 13 of the Health and Safety Code, 
determine if the requirement or order made is 
reasonably consistent with the fire and panic 
safety regulations adopted by the Office of the 
State Fire Marshal and building standards 
relating to fire and panic safety published in the 
California Building Code. 

Any person may request a code 
interpretation from the State Fire Marshal 
relative to the intent of any regulation or 
provision adopted by the State Fire Marshal. 
When the request relates to a specific project, 
occupancy or building, the State Fire Marshal 
shall review the issue with the appropriate local 
enforcing agency prior to rendering such code 
interpretation. 

1 1 1.2. 1.3 Pursuant to Health and Safety Code 
Section 13112, any person who violates any 
order, rule or regulation of the state fire marshal 
is guilty of a misdemeanor punishable by a fine 
of not less than $100.00 or more than $500.00, 
or by imprisonment for not less than six months, 
or by both. A person is guilty of a separate 
offense each day during which he or she commits, 
continues or permits a violation of any provision 



of, or any order, rule or regulation of, the state 
fire marshal as contained in this code. 

Any inspection authority who, in the 
exercise of his or her authority as a deputy state 
fire marshal, causes any legal complaints to be 
filed or any arrest to be made shall notify the state 
fire marshal immediately following such action. 

111.2.2 Right of entry. The fire chief of any city, 
county or fire-protection district, or such person's 
authorized representative, may enter any state 
institution or any other state-owned or state-occupied 
building for the purpose of preparing a fire- 
suppression preplanning program or for the purpose 
of investigating any fire in a state-occupied building. 

The State Fire Marshal, his or her 
deputies or salaried assistants, the chief of any city or 
county fire department or fire protection district and 
his or her authorized representatives may enter any 
building or premises not used for dwelling purposes 
at any reasonable hour for the purpose of enforcing 
this chapter. The owner, lessee, manager or operator 
of any such building or premises shall permit the 
State Fire Marshal, his or her deputies or salaried 
assistants and the chief of any city or coiinty fire 
department or fire-protection district and his or her 
authorized representatives to enter and inspect them 
at the time and for the purpose stated in this section. 

111.2.3 More Restrictive Fire and Panic 
Safety Building Standards. 

111.2.3.1 Any fire-protection district organized 
pursuant to Health and Safety Code Part 2.7 
(commencing with Section 13800) of Division 12 
may adopt building standards relating to fire and 
panic safety that are more stringent than those 
building standards adopted by the State Fire 
Marshal and contained in the California Building 
Standards Code. For these purposes, the district 
board shall be deemed a legislative body and the 
district shall be deemed a local agency. Any 
changes or modifications that are more stringent 
than the requirements published in the California 
Building Standards Code relating to fire and 
panic safety shall be subject to 101.8.1. 

111.2.3.2 Any fire protection district that 
proposes to adopt an ordinance pursuant to this 
section shall, not less than 30 days prior to 
noticing a proposed ordinance for public hearing, 
provide a copy of that ordinance, together with 
the adopted findings made pursuant to Section 
111.2.3.1, to the city, county, or city and county 
where the ordinance will apply. The city, county, 
or city and county, may provide the district with 
written comments, which shall become part of the 
fire protection district's public hearing record. 



13 



111.2-111.3 



2007 CALIFORNIA MECHANICAL CODE 



111.2.3.3 The fire-protection district shall 
transmit the adopted ordinance to the city, 
county, or city and county where the ordinance 
will apply. The legislative body of the city, 
county, or city and county, may ratify, modify or 
deny an adopted ordinance and transmit its 
determination to the district within 15 days of 
the determination. Any modification or denial of 
an adopted ordinance shall include a written 
statement describing the reasons for any 
modifications or denial. No ordinance adopted by 
the district shall be effective until ratification by 
the city, county, or city and county where the 
ordinance will apply. Upon ratification of an 
adopted ordinance, the city, county, or city and 
county, shall file a copy of the findings of the 
district, and any findings of the city, county, or 
city and county, together with the adopted 
ordinance expressly marked and identified to 
which each finding refers, in accordance with 
Section 101.8.1:3. 

111.2.4 Request for alternate means of 
protection. Requests for approval to use an 
alternative material, assembly or materials, equipment, 
method of construction, method of installation of 
equipment, or means of protection shall be made in 
writing to the enforcing agency by the owner or the 
owner's authorized representative and shall be 
accompanied by a full statement of the conditions. 
Sufficient evidence or proof shall be submitted to 
substantiate any claim that may be made regarding its 
conformance. The enforcing agency may require tests 
and the submission of a test report from an approved 
testing organization as set forth in Title 19, California 
code of Regulation, to substantiate the equivalency of 
the proposed alternative means of protection. 

The authority having jurisdiction may 
consider implementation of the findings and 
recommendations identified in a Risk Management 
Plan (RMP) as developed in accordance with Title 
19, Division 2, Chapter 3, when evaluating requests 
for alternative means of protection. 

Approval of a request for use of an 
alternative material, assembly of materials, 
equipment, method of construction, method of 
installation of equipment, or means of protection 
made pursuant to these provisions shall be limited to 
the particular case covered by request and shall not be 
construed as establishing any precedent for any 
future request. 

111.2.5 Appeals. When a request for an alternate 
means of protection has been denied by the enforcing 
agency, the applicant may file a written appeal to the 
state fire marshal for consideration of the applicant's 



proposal. In considering such appeal, the state fire 
marshal may seek the advice of the State Board of Fire 
Services. The State Fire Marshal shall, after 
considering all of the facts presented, including any 
recommendations of the State board of Fire Services, 
determine if the proposal is for the purposes intended, 
at least equivalent to that specified in these 
regulations in quality, strength, effectiveness, fire 
resistance, durability and safety, and shall transmit 
such findings and any recommendations to the 
applicant and to the enforcing agency. 

111.3 Construction Documents. In addition to the 
provisions of this Section, see Title 24, Part 2, California 
Building Code, Appendix Chapter 1, Section 106 for 
additional requirements. 

111.3.1 Pubiic sctiools. Plans and specifications 
for the construction, alteration or addition to any 
building owned, leased or rented by any public school 
district shall be submitted to the Division of the State 
Architect, Office of Regulation Services for review 
and approval. 

Exception: Upon the annual submission of a 
written request by the chief of any city, county, 
or city and county fire department or fire- 
protection district to the Division of the State 
Architect, Office of Regulation Services, 
approvals required by this subsection shall be 
obtained from the appropriate chief or his or her 
authorized representative. In such instances 
plans and specifications may be submitted to the 
State Fire Marshal for relay to the appropriate 
local authority or may be submitted directly to 
such local authority. 

111.3.2 Movable walls and partitions. Plans or 
diagrams shall be submitted to the enforcing agency 
for approval before the installation of, or 
rearrangement of, any movable wall or partition in 
any occupancy. Approval shall be granted only if 
there is no increase in the fire hazard. 

111.3.3 New construction tiigh-rise buildings. 

1. Complete plans or specifications, or both, shall be 
prepared covering all work required to comply 
with new construction high-rise buildings. Such 
plans and specifications shall be submitted to the 
enforcing agency having jurisdiction. 

2. All plans and specifications shall be prepared 
under the responsible charge of an architect or a 
civil or structural engineer authorized by law to 
develop construction plans and specifications, or 
by both such architect and engineer. Plans and 
specifications shall be prepared by an engineer 
duly qualified in that branch of engineering 
necessary to perform such services. Administration 
of the work of construction shall be under the 



14 



ADMINISTRATION 



111.3-111.4 



^^ 



. charge of the responsible architect or engineer 
except that where plans and specifications involve 
alterations or repairs, such work of construction 
may he administered by an engineer duly qualified 
to perform such services and holding a valid 
certificate under Chapter 7 (commencing with 
Section 65700) of Division 3 of the Business and 
Professions Code for performance of services in 
that branch of engineering in which said plans; 
specifications and estimates arid work of 
construction are applicable. 

This section shall not be construed as 
preventing the design of fire-extinguishing 
systems by persons holding a C-16 license issued 
pursuant to Division 3, Chapter 9,- Business and 
Professions Code. In such instances, however, the 
responsibility charge of this section shall prevail. 

111.3.4 Existing iiigli-rise buildings. 

1. Complete plans or specifications, or both, shall be 
prepared covering all work required by Section 
3412, for existing high-rise buildings. Such 
plans or specifications shall be submitted to the 
enforcing agency having jurisdiction. 

2. When new construction is required to conform 
with the provisions of these regulations, complete 
plans or specifications, or both, shall be prepared 
in accordance with the provisions of this 
subsection. As used in this section "new 
construction" is not intended to' include repairs, 
replacements or minor alterations which do not 
disrupt or appreciably add to or affect the 
structural aspects of the building. 

111.3.5 Retention of Plans. Refer to Building 
Standards Law, Health and Safety Code Sections 
19850 and 19851, for permanent retention of plans. 

111.4 Fees 

111.4.1 Ottier fees. Pursuant to Health and Safety 
Code Section 13146.2, a city, county or district which 
inspects a hotel, motel, lodging house, or apartment 
house may charge and collect a fee for the inspection 
from the owner of the structure in an amount, as 
determined by the city, county or district, sufficient 
to pay its costs of that inspection. 

111.4.2 Large Family Day Care. Pursuant to 
Health and Safety Code Section 1597.46, Large 
Family Day-care Homes, the local government shall 
process any required permit as economically as 
possible, and fees charged for revieio shall not exceed 
the costs of the review and permit process. 

111.4.3 High-Rlse. Pursuant to Health and Safety 
Code Section 13217, High-rise Structure Inspection: 
Fees and Costs, a local agency which inspects a high- 
rise structure pursuant to Health and Safety Code 



Section 13217 may charge and collect a fee for the 
inspection from the owner of the high-rise structure 
in an amount, as determined by the local agency, 
sufficient to pay its costs of that inspection. 

111.4.4 Fire Clearance Preinspection, 

Pursuant to Health and Safety Code Section 13235, 
Fire Clearance Preinspection, fee; upon receipt of a 
request from a prospective licensee of a community 
care facility, as defined in Section 1502, of a 
residential-care facility for the elderly, as defined in 
Section 1569.2, or of a child day-care facility , as 
defined in Section 1596.750, the local fire enforcing 
agency, as defined in Section 13244, or state fire 
marshal, whichever has primary jurisdiction, shall 
conduct a preinspection of the facility prior to the 
final fire clearance approval. At the time of the 
preinspection, the primary fire enforcing agency shall 
price consultation and interpretation of the fire safety 
regulations, and shall notify the prospective licensee 
of the facility in writing of the specific fire safety 
regulations which shall be enforced in order to obtain 
fire clearance approval. A fee of not more than $50.00 
may be charged for the preinspection of a facility with 
a capacity to serve 25 or fewer persons. Af^s. of not 
more than $100.00 may be charged for a 
preinspection of a facility with a capacity to serve 26 
or more persons. 

111.4.5 Care Facilities. The primary fire enforcing 
agency shall complete the final fire clearance 
inspection for a community care facility, residential- 
care facility for the elderly, or child day-care facility 
within 30 days of receipt of the request for the final 
inspection, or as of the date the prospective facility 
requests the final prelicensure inspection by the State 
Department of Social Services, whichever is later. 

Pursuant to Health and Safety Code 
Section 13235, a preinspection fee of not more than 
■ $50 may be charged for a facility with a capacity to 
serve 25 or less clients. A fee of not more than $100 
may he charged for a preinspection of a facility with a 
capacity to serve 26 or more clients. 

Pursuant to Health and Safety Code 
Section 13131.5, a reasonable final inspection fee, not 
to exceed the actual cost of inspection services 
necessary to complete a final inspection may be 
charged for Occupancies classified as residential care 
facilities for the elderly (RCFE). 

Pursuant to Health and Safety Code 
Section 1569.84, neither the state fire marshal nor 
any local public entity shall charge any fee for 
enforcing fire inspection regulations pursuant to 
state law or regulation or local ordinance, with 
respect to residential-care facilities for the elderly 
(RCFE) which service six or fewer persons. 



15 



111.4-114.0 



2007 CALIFORNIA MECHANICAL CODE 



111.4.6 Requests of the Office of the State 
Fire Marshal Requests. Whenever a local 
authority having jurisdiction requests that the State 
Fire Marshal perform plan review and/or inspection 
services related to a building permit, the applicable 
fees for such shall be payable to the Office of the State 
Fire Marshal. 

111.5 Inspections. 

111.5.1 Existing Group 1-1 or R occupancies. 

Licensed 24-hour care in a Group I-l or R occupancy 
in existence and originally classified under previously 
adopted state codes be reinspected under the 
appropriate previous code provided there is no change 
in the use or character which would place the facility 
in a different occupancy group. 

111.6 Certificate of Occupancy. A Certificate of 
Occupancy shall be issued as specified in Title 24, Part 2, 
California Building Code, Appendix Chapter 1, Section 110. 

Exception: Group R-3 and Group U Occupancies. 

111.7 Temporary Structures and Uses. See Title 24, 
Part 2, California Building Code, Appendix Chapter 1, 
Section 107. 

111.8 Service Utilities. See Title 24, Part 2, California 
Building Code, Appendix Chapter 1, Section 111. 

111.9 Stop Work Order. See Title 24, Part 2, California 
Building Code, Appendix Chapter 1, Section 114. 

111.10 Unsafe Buildings, Structures and 
Equipment. See Title 24, Part 2, California Building 
Code, Appendix Chapter 1, Section 115. 

1 12.0 Reserved for the State Librarian. 



113.0 Reserved for the Department of Water 
Resources. 



114.0 Reserved for the State Lands Commission. 



16 



CHAPTER 2 

DEFINITIONS 



201.0 General. 

For the purpose of this code, certain abbreviations, 
terms, phrases, words, and their derivatives shall be 
construed as specified in this chapter. Words used ia 
the singular include the plural, and the plural the 
singular. Words used in the masculine gender 
include the feminine, and the feminine the masculine. 

202.0 Accepted Meanings. 

Except as defined in this chapter or elsewhere in this 
code, the interpretation of words used in this code 
shall be in accordance with the meariings defined in 
the applicable building, electric, fire, or plumbing 
code and Webster's Third New International Dictionary 
of the English Language, Unabridged, copyright 1993. 



203.0 



-A- 



ABSORPTION UNIT - An absorption refrigeration 
system that has been factory-assembled and tested 
prior to its installation. 

ACCESSIBLE - Having access to but which first may 
require the removal of an access panel, door, or 
similar obstruction covering the item described. 

ACCESSIBLE, READILY - Capable of being reached 
safely and quickly for operation, repair, or inspection 
without requiring those to whom ready access is 
requisite to climb over or remove obstacles, or to 
resort to the use of portable access equipment. 

AIR, COMBUSTION. See Combustion Air. 

AIR, CONDITIONED - Air that has been treated to 
achieve a desired level of temperature, humidity, or 
cleanliness. 

AIR, EXHAUST - Air being removed from any space 
or piece of equipment and conveyed directly to the 
atmosphere by means of openings or ducts. 

AIR-HANDLING UNIT - A blower or fan used for the 
purpose of distributing supply air to a room, space, 
or area. 

AIR, MAKEUP - Air that is provided to replace air 
being exhausted. 

AIR-MOVING SYSTEM - A system designed to 
provide heating, cooling, or ventilation in which one 
or more air-handling imits are used to supply air to a 



common space or are drawing air from a common 
plenum or space. 

AIR, OUTSIDE - Air from outside the building 
intentionally conveyed by openings or ducts to 
rooms or to conditiorting equipment. 

AIR, RELIEF - [OSHPD 1, 2, 3 & 4] is air being 
exhausted directly from a building or a return duct system 
which is not contaminated by odors or other contaminants 
and could otherwise be used as return air if not exhausted 
from the building. 

AIR, RETURN - Air from the conditioned area that is 
returned to the conditioning equipment for 
reconditioning. 

AIR, SUPPLY - Air being conveyed to a conditioned 
area through ducts or plenums from a heat 
exchanger of a heating, cooling, absorption, or 
evaporative cooling system. 

APPLIANCE - A device that utilizes fuel or other 
forms of energy to produce light, heat, power, 
refrigeration, or air-conditioning. This definition also 
shall include a vented decorative appliance. 

APPROVED - Acceptable to the Authority Having 
Jurisdiction. 

Exception: [HCD 1 and 2] "Approved" means 
meeting the approval of the Enforcing Agency, except 
as otherwise provided by law, when used in connection 
with any system, material, type of construction, 
fixture or appliance as the result of investigations and 
tests conducted by the agency, or by reason of accepted 
principles or tests by national authorities, or technical, 
health, or scientific organizations or agencies. 

Notes: 

(1) See Health and Safety Code Section 17920 for 
"Approved" as applied to residential construction 
and buildings or structures accessory thereto, as 
referenced in Sections 108.2.1.1 and 108.2.1.2. 

(2) See Health and Safety Code Section 17921.1 for 
"Approved" as applied to the use of hotplates in 
residential construction referenced in Sections 
108.2.1.1 and 108.2.1.2. 

(3) See Health and Safety Code Section 17921.3 for 
"Approved" as applied to low-flush water closets 
in residential construction, as referenced in 
Sections 1082.1.1 and 108.2.1.2. 

(4) See Health and Safety Code Section 19966 for 
"Approved" as applied to Factory-Built Housing 
as referenced in Sections 108.2.1.1 and 108.2.1.2. 



17 



203.0 - 204.0 



2007 CALIFORNIA MECHANICAL CODE 



(5) See Health and Safety Code Section 18201 for 
"Approved" as applied to Mobilehome Parks as 
referenced in Section 108.2.1.3. 

(6) See Health and Safety Code Section 18862.1 for 
"Approved" as applied to Special Occupancy 
Parks as referenced in Section 108.2.1.3. 

APPROVED TESTING AGENCY - An organization 
primarily established for purposes of testing to 
approved standards and approved by the Authority 
Having Jurisdiction. [UPC: 203.0] [HCD 1 and HCD 

2] "Approved Testing Agency" is any agency which is 
determined by the Enforcing Agency, except as otherwise 
provided by statute, to have adequate personnel and 
expertise to carry out the testing of systems, materials, 
and various types of construction, fixtures or appliances. 

ASSEMBLY BUILDING - A building or a portion of 
a building used for the gathering together of fifty 
(50) or more persons for such purposes as 
deliberation, education, instruction, worship, 
entertainnient, amusement, drinking, dining, or 
awaiting transportation. [HCD 1, HCD 2 and SFM] 
Refer to the California Building Code, Title 24, Part 2 for 
use and occupancy classification. 
AUTHORITY HAVING JURISDICTION - The 
organization, office, or individual responsible for 
enforcing the requirements of a code or standard, or 
for approving equipment, materials, installations, or 
procedures. The Authority Having Jurisdiction shaU 
be a federal, state, local, or other regional department 
or an individual such as a plumbing official, 
mechanical official, labor department official, health 
department official, building official, or others 
having statutory authority. In the absence of a 
statutory authority, the Authority Having Jurisdiction 
may be some other responsible party. This definition 
shall include the Authority Having Jurisdiction's 
duly authorized representative. [HCD 1, HCD 2 and 
SFM] "Authority Having Jurisdiction" shall mean 
"Enforcing Agency" as defined in Section 207.0 of 
this code. 

AUTOMATIC - That which provides a function 
without the necessity of human intervention. [NFPA 
96: 3.3.6] 

AZEOTROPE - A refrigerant blend comprising 
multiple components of different volatiles that, 
when used in refrigeration cycles, do not change 
volumetric composition or saturation temperature 
as they evaporate or condense at constant pressure. 

204.0 -B- 

BOILER, HIGH-PRESSURE - A boiler furnishing 

steam at pressures in excess of fifteen (15) pounds 



per square inch (103.4 kPa) or hot water at 
temperatures in excess of 250°F (121°C) or at 
pressures in excess of 160 pounds per square inch 
(1102.4 kPa). 

BOILER ROOM - Any room containing a steam or 
hot water boiler. 

BREATHING ZONE - The region within an occupied 
space between three planes 3 and 71 inches (75 and 
1,800 mm) above the floor and more than 2 feet (600 
mm) from the walls or fixed air-conditioning 
equipment. [ASHRAE 62.1:3] 

BREATHING ZONE OUTDOOR AIRFLOW {Vbz) - 

The rate of outdoor airflow required in the breathing 
zone of an occupiable space. 

BREECHING - A metal connector for medium- and 

high-heat appliances. 

BRINE - As determined in accordance with NFPA 30. 

BTU/H - The listed maximum capacity of any 

appliance, absorption unit, or burner expressed in 

British thermal units input per hour, unless 

otherwise noted. 

BUILDING - [HCD 1 and HCD 2] Any structure used 

or intended for supporting or sheltering any use or 

occupancy. 

Exceptions: "Building" shall not include the 
following: 

(1) Any mobilehome as defined in Health and Safety 
Code Section 18008. 

(2) Any manufactured home as defined in Health 
and Safety Code Section 18007. 

(3) Any commercial modular as defined in Health 
and Safety Code Section 18001.8 or any special 
purpose commercial modular as defined in 
Health and Safety Code Section 18012.5. 

(4) Any recreation Vehicle as defined in Health and 
Safety Code Section 18010. 

(5) Any multi-unit manufactured housing, as 
defined in Health and Safety Code Section 
18008.7. 

For additional information, see Health and Safety 
Code Section 18908. 

BUILDING CODE - The building code that is 
adopted by this jurisdiction. [HCD 1, HCD 2 and 
SFM] "Building Code" shall mean the California 
Building Code, Title 24, Part 2. [OSHPD 1, 2, 3 & 4] 

For purpose of the California Mechanical Code, "Building 
Code" shall be the most recent edition of the California 
Building Code. 

BUILDING OFFICIAL - See Authority Having 
Jurisdiction. For applications listed in Section 111 
regulated by the Office of the State Fire Marshal "Building 
Official" is the officer charged with the administration and 
enforcement of this code, or a regular deputy. See 



18 



DEFINITIONS 



204.0-205.0 



"Enforcing Agena/". For the State of California, "Building 
Official" shall be the "Enforcing Agency" as specified in 
Section 111. [For OSHPD 1, 2, 3 & 4] For the State of 
California, "Building Official" shall he the "Enforcing 
Agency" as specified in Section 108.0. 

205.0 -C- 

CAS NUMBER - The Chemical Abstract System 
registry number. 

CENTRAL HEATING PLANT or HEATING PLANT - 

Environmeiital heating equipment installed in a 
manner to supply heat by means of ducts or pipes to 
areas other than the room or space in which the 
equipment is located. 

CERTIFIED - A formally stated recognition and 
approval of an acceptable level of competency, 
acceptable to the Authority Having Jurisdiction. 
[NFPA 96 3.3.9] 

CHIMNEY - A vertical shaft enclosing one or more 
flues for conveying flue gases to the outside 
atmosphere. 

Factory-Built Chimney - A listed chimney. 

Masonry Chimney - A chimney of solid 
masonry units, bricks, stones, listed masonry 
units, or reinforced concrete, lined with suitable 
flue liners. 

Metal Chimney - A chimney constructed of 
metal with a minimum thickness not less than 
0.127 inch (3.23 mm) (No. 10 manufacturer's 
standard gauge) steel sheet. 

CHIMNEY CLASSIFICATIONS: 

Chimney, Residential Appliance-Type - A 

factory-built or masonry chimney suitable for 
removing products of combustion from resi- 
dential-tjrpe appliances producing combustion 
gases not in excess of 1,000°F (538°C), measured 
at the appliance flue outlet. Factory-built Type 
HT chimneys have high-temperature thermal 
shock resistance. 

Chimney, Low-Heat Appliance-Type - A 

factory-built, masonry, or metal chimney suitable 
for removing the products of combustion from 
fuel-burning low-heat appliances producing 
combustion gases not in excess of 1,000°F (538°C) 
Tinder normal operating conditions, but capable 
of producing combustion gases of 1,400°F (760°C) 
during intermittent forced firing for periods up 
to one hour. All temperatures are measured at 
the appliance flue outlet. 

Chimney, Medium-Heat Appliance-Type - A 

factory-built, masoivry, or metal chimney suitable 

for removing the products of combustion from 

: fuel-burning mediimi-heat appliances producing 



combustion gases not in excess of 2,000°F 
(1,093°C), measured at the appliance flue outlet. 

Chimney, High-Heat Appliance-Type - A 

factory-built, masonry, or metal chimney suitable 
for removing the products of combustion from 
fuel-burning high-heat appliances producing 
combustion gases in excess of 2,000°F (1,093°C), 
measured at the appliance flue outlet. 

CHIMNEY CONNECTOR - The pipe that coimects a 
fuel-burning appliance to a chimney. 

CLOSED COMBUSTION SOLID-FUEL-BURNING 
APPLIANCE - A heat-producing appliance that 
employs a combustion chamber that has no openings 
other than the flue collar, fuel-charging door, and 
adjustable openings provided to control the amount 
of combustion air that enters the combustion chamber. 
CLOSET - See Confined Space. 

CLOTHES DRYER - A appliance used to dry wet 
laundry by means of heat derived from the 
combustion of fuel gases. 

CLOTHES DRYER, TYPE 1 - Primarily used in 
family living environment. May or may not be coin 
operated for public use. [NFPA 54: 3.3.18.1] 

CLOTHES DRYER, TYPE 2 - Used in business with 
direct intercourse of the function with the public. 
May or may not be operated by public or hired 
attendant. May or may not be coin operated. [NFPA 
54:3.3.18.2] 

CODE - A standard that is an extensive compilation 
of provisions covering broad subject matter or that is 
suitable for adoption into law independently of other 
codes and standards. 

COMBUSTION AIR - The total amount of air 
provided to the space that contains fuel-burning 
equipment. Includes air for fuel combustion, draft 
hood dilution, and ventilation of the equipment 
enclosure. 

COMPRESSOR, POSITIVE DISPLACEMENT - A 

compressor in which increase in pressure is attained 
by changing the internal volume of the compression 
chamber. 

COMPRESSOR, REFRIGERANT - A machine, with 
or without accessories, for compressing a refrigerant 
vapor. 

CONDENSER - The part of the system designed to 
Uquefy refrigerant vapor by removal of heat. 

CONDENSING APPLIANCE - An appliance that 
condenses part of the water vapor generated by the 
burning of hydrogen in fuels. 

CONDENSING UNIT - A mechanical refrigeration 



19 



205.0 - 207.0 



2007 CALIFORNIA MECHANICAL CODE 



system, consisting of one or more power-driven 
compressors, condensers, liquid receivers if 
provided, and the regularly furnished accessories 
that have been factory assembled and tested prior to 
its installation. 

CONDITIONED SPACE - An area, room, or space 
normally occupied and being heated or cooled for 
human habitation by any equipment. 

CONFINED SPACE - A room or space having a 
volume less than fifty (50) cubic feet (1.42 m') per 
1000 Btu/h (293 W) of the aggregate input rating of 
all fuel-burning appliances installed in that space. 

COOLING - Air cooling to provide a room or space 
temperature of 68°F (20°C) or above. 

COOLING SYSTEM - AH of that equipment, 
including associated refrigeration, intended or 
installed for the purpose of cooling air by mechanical 
means and discharging such air into any room or 
space. This definition shall not include any 
evaporative cooler. 

COOLING UNIT - A self-contained refrigeration 
system that has been factory assembled, tested, and 
installed with or without conditioned air and ducts, 
without connecting any refrigerant-containing parts. 
This definition shall not include a portable cooling 
unit or an absorption unit. 

206.0 -D- 

DAWIPERS shall be defined as follows: 

Fire Damper - An automatic-closing metal 
assembly of one or more louvers, blades, slats, or 
vanes compljong with recognized standards. 

Smoke Damper - A damper arranged to seal off 
airflow automatically through a part of an air 
duct system, so as to restrict .the passage of smoke. 

Volume Damper - Any device that, when 
installed, will restrict, retard, or direct the flow 
of air in any duct, or the products of combustion 
in any heat-producing equipment, its vent 
connector, vent, or chimney. 

DEPARTMENT - For applications listed in Section 
108.2 regulated by the Department of Housing and 
Community Development, "Department" means the 
Department of Housing and Community Development. 

DESIGN FLOOD ELEVATION - The elevation of the 
"design flood," including wave height, relative to the 
datum specified on the community's legally 
designated flood hazard map. 

DIRECT GAS-FIRED MAKEUP AIR HEATER - A 

heater in which all the products of combustion 
generated by the gas-burning device are released 
into the outside akstream being heated. 



DIRECT VENT APPLIANCE - An appHance that is 
constructed and installed so that all air for 
combustion is derived from the outside atmosphere 
and all flue gases are discharged to the outside 
atmosphere. 

DISTRICT HEATING PLANT - A power boiler plant 
designed to distribute hot water or steam to users 
located off the premises. 

DRAFT HOOD - A device built into an appliance or 
made a part of the vent connector from an appliance, 
that is designed to: 

(1) Assure the ready escape of the flue gases in 
the event of no draft, back draft, or stoppage 
beyond the draft hood. 

(2) Prevent a back draft from entering the 
appliance. 

(3) Neutralize the effect of stack action of the 
chimney or gas vent upon the operation of 
the appliance. 

DUCT - Any tube or conduit for trarisnussion of air, 
fumes, vapors, or dusts. This definition shall not 
include: 

(1) A vent, vent connector, or chimney connector. 

(2) Any tube or conduit wherein the pressure of 
the air exceeds one (1) pound per square inch. 

(3) The air passages of listed self-contained 
systems. 

DUCT FURNACE - A warm-air furnace normally 
installed in an air-distribution duct to supply warm air 
for heating. This definition shall apply oiily to a warm- 
air heating appUance that depends for air circulation 
on a blower not furnished as part of the furnace. 

DUCT SYSTEM - Includes all ducts, duct fittings, 
plenums, and fans assembled to form a continuous 
passageway for the distribution of air. 

DWELLING - A building or portion thereof that 
contains not more than two dwelling units. 

DWELLING UNIT - A building or portion thereof 
that contains living facilities, including provisions 
for sleeping, eating, cooking, and sanitation, as 
required by this code, for not more than one family. 

207.0 -E- 

ELECTRIC HEATING APPLIANCE - A device that 
produces heat energy to create a warm environment 
by the application of electric power to resistance 
elements, refrigerant compressors, or dissimilar 
material junctions. 

ELECTRICAL CODE - The National Electrical Code 
promulgated by the National Fire Protection 
Association, as adopted by this jtiriisdiction. [HCD 1 
and HCD 2] Whenever the term "Electrical Code" is used 



20 



DEFINITIONS 



207.0-210.0 



in this code, it shall mean the California Electrical Code, 
Title 24, Part 3. 

Enforcing Agency -[HCD 1 and HCD 2] "Enforcing 
Agency" is the designated department or agency as 
specified by statutes and regulation. [SFM, OSHPD 1, 2, 

3 & 4] is the designated department or agency as specified 
in statutes to enforce the specific building standards 
promulgated or adopted by the specified state agency. 

EQUIPMENT - A general term includmg materials, 
fittings, devices, appliances, and apparatus used as 
part of or in connection with installations regulated 
by this code. 

EVAPORATIVE COOLER - A device used for 
reducing the sensible heat of air for cooling by the 
process of evaporation of water into an airstream. 

EVAPORATIVE COOLING SYSTEM - All of that 
equipment intended or installed for the purpose of 
environmental cooling by an evaporative cooler 
from which the conditioned air is distributed 
through ducts or plenums to the conditioned area. 

EVAPORATOR - That part of a refrigeration system 
in which liquid refrigerant is vaporized to produce 
refrigeration. 



208.0 



-F- 



FAMILY [HCD 1 and HCD 2] - "Family" is an 
individual or two or more persons who by blood or 
marriage, or otherwise, live together in a dwelling unit. 

FIRE CODE - Whenever the term "Fire Code" is used in 
this code, it shall mean the California Fire Code. 

FIREPLACE STOVE - A chimney-connected, 
solid-fuel-burning stove (appliance) having part of 
its fire chamber open to the room. 

FIRE-RESISTIVE CONSTRUCTION - Constructiori 
complying with the requirements of the Building 
Code for the time period specified. 

FLOOD HAZARD AREA - The greater of the 
following two areas: 

(1) The area within a floodplain subject to a 1 
percent or greater chance of flooding in any 
given year. 

(2) The area designated as a flood hazard area 
on a community's flood hazard map, or 
otherwise legally designated. 

FLOOD HAZARD AREA SUBJECT TO HIGH 
VELOCITY WAVE ACTION - Area within the flood 
hazard area that is subject to high-velocity wave 
action, and shown on a Flood Insurance Rate Map or 
other flood hazard map as Zone V, VO, VE or Vl-30. 

FLOOR FURNACE - A completely self-contained 
furnace suspended from the floor of the space being 
heated, taking air for combustion from outside such 



space and with means for observing flames and 
lighting the appliance from such space. 

FORCED-AIR-TYPE CENTRAL FURNACE - A 

central furnace equipped with a fan or blower that 
provides the primary means for circulation of air. 

Horizontal-Type Central Furnace - A furnace 
designed for low-headroom installations with 
airflow through the appliance in a horizontal 
path. 

Upflow-Type Central Furnace - A furnace 
designed with airflow essentially in a vertical 
path, discharging air at or near the top of the 
furnace. 

Downflow-Type Central Furnace - A furnace 
designed with airflow essentially in a vertical 
path, discharging air at or near the bottom of the 
furnace. 

Enclosed Furnace - A specific heating or 
heating and ventilating furnace incorporating an 
integral total enclosure and using only outside 
air for combustion. 

FRACTIONATION - A change, in composition of a 
blend by preferential evaporation of the more 
volatile component or condensation of the less 
volatile component. 

FUSIBLE PLUG - A device arranged to relieve 
pressure by operation of a fusible member at a 
predetermined temperature. 



209.0 



-G- 



GALVANIZED STEEL - Any steel conforming to the 
requirements of UMC Standard No. 2-2. 

GENERATOR - A device equipped with a means of 
heating used in an absorption system to drive 
refrigerant out of solution. 

GRAVITY HEATING SYSTEM - Any heating system 
consisting of a gravity-type warm-air furnace, 
together with all air ducts or pipes and accessory 
apparatus installed in connection therewith. 

GRAVITY-TYPE WARM-AIR FURNACE - A warm- 
air furnace depending primarily on circulation of air 
through the furnace by gravity. This definition also 
shall include any furnace approved with a 
booster-type fan that does not materially restrict free 
circulation of air through the furnace when the fan is 
not in operation. 

210.0 -H- 

HAZARDOUS LOCATION - Any area or space 
where combustible dust, ignitable fibers or 



21 



210.0-214.0 



2007 CALIFORNIA MECHANICAL CODE 



flammable, volatile liquids, gases, vapors or 
mixtures are or may be present in. the air in 
quantities sufficient to produce explosive or ignitable 
mixtures. 

HEALTH FACILITIES [OSHPD 1,2, 3 & 4] are those 
buildings specified within the statutory authority of the 
Office of Statewide Health Planning and Development. 

HEAT (ENERGY) RECOVERY VENTILATOR - A 

device intended to remove air from buildings, 
replace it with outside air, and in the process transfer 
heat from the warmer to the colder airstreams. 

HEATING DEGREE DAY - A unit, based upon 
temperature difference and time, used in estimating 
fuel consumption and specifying nominal armual 
heating load of a building. For any one day when the 
mean temperature is less than 65°F (18°C), there exist 
as many degree days as there are Fahrenheit degrees 
difference in temperature between mean temperature 
for the day and 65°F (18°C). 

HEATING EQUIPMENT - Includes all warm-air 
furnaces, warm-air heaters, combustion products 
vents, heating air-distribution ducts and fans, and all 
steam and hot water piping, together with aU control 
devices and accessories installed as part of, or in 
connection with, any environmental heating system 
or appliance regxilated by this code. 

HEATING SYSTEM - A warm air heating plant 
consisting of a heat exchanger enclosed in a casing, 
from which the heated air is distributed through 
ducts to various rooms and areas. A heating system 
includes the outside air, return air and supply air 
system, and all accessory apparatus and equipment 
installed in connection therewith. 

HEAT PUMP - A refrigeration system that extracts 
heat from one substance and transfers it to another 
portion of the same substance or to a second substance 
at a higher temperature for a beneficial purpose. 

HIGH SIDE - The parts of a refrigeration system 
subjected to approximately condenser pressure. 
HOOD - An air-intake device connected to a 
mechanical exhaust system for collecting vapors, 
fumes, smoke, dust, steam, heat or odors from, at, or 
near the equipment, place, or area where generated, 
produced, or released. 

211.0 -I- 

IDLH (Immediately Dangerous to Life and Health) - 

A concentration of airborne contaminants, normally 
expressed in parts per nniUion (ppm) or milligrams 
per cubic meter (mg/m^), that represents the 
maximum level from which one could escape within 



thirty (30) minutes without any escape-impairing 
symptoms or irreversible health effects. This level is 
established by the National Institute of Occupational 
Safety and Health (NIOSH). 

INDUSTRIAL HEATING EQUIPMENT - Includes 
appliances, devices, or equipment used, or intended 
to be used, in an industrial, manufacturing, or 
commercial occupancy for applying heat to any 
material being processed, but shall not include water 
heaters, boilers, or portable equipment used by 
artisans in pursuit of a trade. 

INSANITARY LOCATION - An area, space, or room 
where the air is imfit or xmdesirable for circulation to 
occupied parts of a btdlding. 



212.0 



-J- 



JOINT, BRAZED - Any joint obtained by joining of 
metal parts with alloys that melt at temperatures 
higher than 840°F (449°C) but lower than the melting 
temperature of the parts being joined. 

JOINT, COMPRESSION - Any multipiece joint with 
cup-shaped threaded nuts that, when tightened, 
compress tapered sleeves so that they form a tight 
joint on the periphery of the tubing they connect. 

JOINT, FLANGED - One made by bolting together a 
pair of flanged ends. 

JOINT, FLARED - Any metal-to-metal compression 
joint in which a conical spread is made on the end of 
a tube that is compressed by a flare nut against a 
mating flare. 

JOINT, MECHANICAL - General form for gastight 
joints obtained by the joining of metal parts through 
a positive holding mechanical construction (such as 
flanged joint, screwed joint, or flared joint). 

JOINT, SOLDERED - A joint made by the joining of 
metal parts with metalUc mixtures or aUoys that melt 
at a temperature up to and including 84Q°F (449°C). 

JOINT, WELDED - A gastight joint obtained by the 
joining of metal parts in molten state. 



213.0 

No definitions. 



-K- 



214.0 -L- 

LABELED - Equipment or materials bearing a label 
of a listing agency (accredited conformity assessment 
body). See Listed (Third Party Certified). 
[UFC:214.0] [HCD 1 and HCD 2] "Labeled" means 
equipment or materials to which has been attached a label, 
symbol or other identifying mark of an organization, 



22 



DEFINITIONS 



214.0-215.0 



approved by the Department, that maintains a periodic 
inspection program of production of labeled products, 
installations, equipment, or materials and by whose labeling 
the manufacturer indicates compliance with appropriate 
standards or performance in a specified manner. 

LEL (Lower Explosive Limit). See LFL. 

LFL (Lower Flammable Limit or Lower Limit of 
Flammability) - The minimum concentration of a 
combustible substance that is capable of propagating 
a flame through homogeneous mixture of the 
combustible and a gaseous oxidizer under the 
specified condition of test. The LFL is sometimes 
referred to as LEL (lower explosive limit). For the 
purposes of this definition, LFL and LEL are identical. 

LINE CONTACT INSTALLATION - An installation 
in which a furnace is installed so that building joists, 
studs, or framing are contacted by the furnace jacket 
upon the lines formed by the intersection of the 
jacket sides with the top surface. 

LIQUEFIED PETROLEUM GAS or LPG (LP Gas) - 

Means and includes a material composed pre- 
dominantly of any of the following hydrocarbons or 
mixtures of them: propane, propylene, butanes 
(normal butane or isobutane), and butylenes. When 
reference is made to liquefied petroleum gas in this 
code, it shall refer to liquefied petroleum gases in 
either the liquid or gaseous state. 

LISTED (THIRD PARTY CERTIFIED) - Equipment 
or materials included in a list published by a listing 
agency (accredited conformity assessment body) that 
maintains periodic inspection on current production 
of listed equipment or materials and whose listing 
states either that the equipment or material complies 
with approved standards or has been tested and 
found suitable for use in a specified manner. 
[UPC:214.0] [HCD 1 and HCD 2] "Listed" means all 
products that appear in a list published by an approved 
testing or listing agency. For additional information, see 
Health and Safety Code Section 17920(h). 

LISTED AND LISTING - [SFM] "Listed" and 
"Listing" are terms referring to equipment or materials 
included in a list published by an approved testing 
laboratory, inspection agency or other organization 
concerned with product evaluation that maintains periodic 
inspection of current productions of listed equipment or 
materials and which listing states that the material or 
equipment complies with approved nationally recognized 
codes, standards or tests and has been tested or evaluated 
and found suitable for use in a specific manner. These 
terms shall also mean equipment or materials accepted by 
the State Fire Marshal as conforming to the provisions of 
these regulations and which are included in a list 
published by the State Fire Marshal. 



LISTING AGENCY - An agency accredited by an 
independent and authoritative conformity assessment 
body to operate a material and product listing and 
labeling (certification) system and that is accepted by 
the Authority Having Jurisdiction, which is in the 
business of listing or labeling. The system includes 
initial and ongoing product testing, a periodic 
inspection on current production of listed (certified) 
products, and that makes available a published 
report of such listing in which specific information is 
included that the material or product conforms to 
applicable standards and found safe for use in a 
specific manner. [UPC:214.0] [HCD 1 and HCD 2] 
"Listing Agency" means an agency approved by the 
Department that is in the business of listing and labeling 
products, materials, equipment, and installations tested by 
an approved testing agency, and that maintains a periodic 
inspection program on current production of listed 
products, equipment, and installations, and that, at least 
annually makes available a published report of these 
listings. For additional information, see Health and Safety 
Code Section 17920(i). 

LOW-PRESSURE HOT-WATER-HEATING BOILER - 

A boiler furnishing hot water at pressures not 
exceeding 160 poimds per square inch (1,102.4 kPa) 
and at temperatures not exceeding 250°F (121 °C). 

LOW-PRESSURE STEAM-HEATING BOILER - A 

boiler furnishing steam at pressures not exceeding 
fifteen (15) pounds per square inch (103.4 kPa). 

LOW SIDE - Refers to the parts of a refrigeration 
system subjected to approximate evaporator pressure. 



215.0 



-M- 



MACHINERY - The refrigeration equipment forming 
a part of the refrigeration system, including, but not 
limited to, the following: compressors, condensers, 
liquid receivers, evaporators, and cormecting piping. 

MACHINERY ROOM [SFM] - Machinery Room is a 
room in which a refrigeration system is permanently 
installed and operated but not including evaporators 
located in a cold storage room, refrigerator box, air-cooled 
space or other enclosed space. Closets solely contained 
within, and opening only into, a room shall not be 
considered machinery rooms, but shall be considered a 
part of the machinery rooms in which they are contained 
or open into. It is not the intent of this definition to cause 
the space in which unit or self-contained systems of 
Group I refrigerants are locate to be classified as 
machinery rooms. 

MANUFACTURER - The company or orgaruzation 
that evidences its responsibility by affixing its name, 
trademark, or trade name to equipment or devices. 



23 



215.0-217.0 



2007 CALIFORNIA MECHANICAL CODE 



MANUFACTURER'S INSTALLATION INSTRUC- 
TIONS - Printed instructions included with 
equipment or devices for the purpose of providing 
information regarding safe and proper installation 
whether or not as part of the conditions of listing. 



216.0 



-N- 



NONCOWIBUSTIBLE - As applied to building 
construction material, means a material that in the 
form in which it is used is either one of the 
following: 

(1) Material of which no part will ignite and 
bum when subjected to fire. 

(2) Material having a structural base of 
noncombustible material as defined in 1 
above, with a surfacing material not over 
1/8 inch (3.2 mm) thick that has a flame- 
spread index not higher than fifty (50). 

Noncombustible does not apply to siarface finish 
materials. Material required to be noncombustible 
for reduced clearances to flues, heating 
appliances, or other sources of high temperature 
shall refer to material conforming to 1 above. No 
material shall be classed as noncombustible that 
is subject to increase in combustibility or 
flame-spread index beyond the limits herein 
established, through the effects of age, moisture, 
or other atmopheric condition. 

NUISANCE [HCD 1 and HCD 2] "Nuisance" shall 
mean any nuisance as defined in Health and Safety Code 
Section 17920(k). 

Notes: 

(1) For applications subject to the Mobilehome Parks 
Act as referenced in Section 108.3.2.2 of this 
code, refer to California Code of Regulations, 
Title 25 Division 1, Chapter 2 of the definition of 
"Nuisance". 

(2) For application subject to the Special Occupancy 
Parks Act as referenced in Section 108.3.2.3 of 
this code, refer to California Code of Regulations, 
Title 25, Division 1, Chapter 2.2 for the 
definition of "Nuisance". 

217.0 -O- 

OCCUPANCY - The purpose for which a btdlding or 
part thereof is used or intended to be used. 

OCCUPANCY CLASSIFICATION - For the purpose 
of this code, certain occupancies are defined as 
follows: [HCD 1, HCD 2 and SFM] Refer to the 
California Building Code, Title 24, Part 2 for use and 
occupancy classification. [OSHPD 1, 2, 3 & 4] Shall be 



those as shown in the California Building Code, for the 
purpose of this code, certain occupancies are defined as 
follows: 

Group A Occupancies 

Group A Occupancies include the use of a 
building or structure, or a portion thereof, 
for the gathering together of fifty (50) or more 
persons for purposes such as civic, social, or 
religious functions, recreation, education or 
instruction, food or drink consumption, or 
awaiting transportation. A room or space used 
for assembly purposes by less than fifty (50) 
persons and accessory to another occupancy 
shall be included as a part of that major 
occupancy. Assembly occupancies shall include 
the following: 

Division 1. A building or portion of a 
building having an assembly room with an 
occupant load of 1,000 or more and a 
legititnate stage. 

Division 2. A building or portion of a 
building having an assembly room with an 
occupant load of less than 1,000 and a 
legitimate stage. 

Division 2.1. A btdlding or portion of a 
building having an assembly room with 
an occupant load of 300 or more 
without a legitimate stage, including 
such buildings used for educational 
purposes and not classed as a Group B 
or E Occupancy. 

Division 3. A building or portion of a 
building having an assembly room with an 
occupant load of less than 300 without a 
legitimate stage, including such buildings 
used for educational purposes and not 
classed as a Group B or E Occupancy. 

Division 4. Stadimris, reviewing stands, and 
amusement park structures not included 
within other Group A Occupancies. Specific 
and general requirements for grandstands, 
bleachers, and reviewing stands are in the 
Building Code. 

Exception: Amusement buildings, or 
portions tiiereof, that are without walls or a 
roof and constructed to prevent the 
accumulation of smoke in assembly areas. 

Group B Occupancies 

Group B Occupancies shall include buildings, 
structures, or portions thereof for office, 
professional, or service-type transactions that are 
not classified as Group H Occupancies. Such 
occupancies include occupancies for the storage 



24 



DEFINITIONS 



217.0 



of records and accounts and eating and 
drinking establishments with an occupant load 
of less than fifty (50). 

Group E Occupancies 

Division 1. Any building used for 
educational purposes through the 12th 
grade by fifty (50) or more persons for more 
than twelve (12) hours per week or four (4) 
hours in any one day. 

Division 2. Any building used for 
educational purposes through the 12th 
grade by less than fifty (50) persons for 
more than twelve (12) hours per week or 
four (4) hours in any one day. 

Division 3. Any building or portion thereof 
used for day-care purposes for more than 
six (6) persons. 

Group F Occupancies 

Group F Occupancies shall include the use of a 
building or structure, or a portion thereof, for 
assembling, disassembling, fabricating, 
finishing, manufacturing, packaging, repair, or 
processing operations that are not classified as 
Group H Occupancies. 

Division 1. Moderate-hazard factory and 
industrial occupancies shall include factory 
and industrial uses that are not classified as 
Group F, Division 2 Occupancies. 

Division 2. Low-hazard factory and 
industrial occupancies shall include facilities 
producing noncombustible or nonexplosive 
materials that, during finishing, packing, 
or processing, do not involve a significant 
fire hazard. 

Group H Occupancies 

Group H Occupancies shall include buildings or 
structures, or portions thereof, that involve the 
manufacturing, processing, generation, or 
storage of materials that constitute a high fire, 
explosion, or health hazard. For definitions, 
identification and control of hazardous 
materials and pesticides, and the display of 
nonflammable solid and nonflammable or 
noncombustible liquid hazardous materials in 
Group B, F, M> or S Occupancies, see the Fire Code. 

Division 1. Occupancies with a quantity of 
material in the building in excess of those listed 
in the Building Code, that present a high 
explosion hazard. 

Division 2. Occupancies where combustible 
dust is manufactured, used, or generated in 
such a manner that concentrations and 



conditions create a fire or explosion potential. 

Occupancies with a quantity of material in 
the building in excess of those listed in the 
Building Code that present a moderate 
explosion hazard or a hazard from 
accelerated burning. 

Division 3. Occupancies where flammable 
solids, other than combustible dust, are 
manufactured, used, or generated. 

Division 4. Repair garages not classified as 
Group S, Division 3 Occupancies. 

Division 5. Aircraft repair hangars and 
heliports not classified as Group S, Division 
5 Occupancies. 

Division 6. Semiconductor fabrication 
facilities and comparable research and 
development areas in that hazardous 
production materials (HPM) are used and 
the aggregate quantity of materials is in 
excess of those listed in the Building Code. 

Division 7. Occupancies having quantities 
of materials in excess of those listed in the 
Building Code that are health hazards. 

Group I Occupancies 

Division 1.1. Nurseries for the full-time care 
of children under the age of six (each 
accommodating more than five children). 

Hospitals, sanitariums, nursing homes [For 
OSHPD 1, 2 & 3] and homes for the aged 
with nonambulatory patients, protective 
social-care facilities or homes with non- 
ambulatory guests, and similar buildings 
(each accommodating more than five (5) 
patients). 

Division 1.2. Health care centers for 
ambulatory patients receiving outpatient 
medical care that may render the patient 
incapable of unassisted self-preservation 
(each tenant space accommodating more 
than five (5) such patients). 

• Division 2. Nursing homes for ambulatory 
patients and homes for cliildren six years of 
age or over (each accommodating more than 
five patients or children). 

Division 3. Mental hospitals, mental 
sanitariums, jails, prisons, reformatories, 
and buildings where personal liberties of 
inmates are similarly restrained. 

Group M Occupancies 

Group M Occupancies shaU include buildings, 
structures; or portions thereof, used for the 



25 



217.0-218.0 



2007 CALIFORNIA MECHANICAL CODE 



display and sale of merchandise, and involving 
stocks of goods, wares, or merchandise incidental 
to such purposes and accessible to the public. 

Group R Occupancies 

Division 1. Hotels and apartment houses. 
Congregate residences (each accommodating 
more than ten (10) persons). 

Division 2. Not used. 

Division 3. Dwellings and lodging houses. 
Congregate residences (each accommodating 
ten (10) persons or less). 

Group S Occupancies 

Group S Occupancies shall include the use of a 
building or structure, or a portion thereof, for 
storage not classified as a hazardous occupancy. 

Division 1. Moderate-hazard storage 
occupancies shall include buildings or 
portions of buildings used for storage of 
combustible materials that are not classified as 
Group S, Division 2 or Group H Occupancies. 

Division 2. Low-hazard storage occupancies 
shall include buildings or structures, or 
portions thereof, used for storage of 
noncombustible materials such as products 
on wood pallets or in paper cartons 
with or without single-thickness divisions, 
or in paper wrappings, and shall include ice 
plants, power plants, and pumping plants. 

Division 3. Division 3 Occupancies shall 
include repair garages where work is Umited 
to exchange of parts and maintenance 
requiring no open flame or welding, motor 
vehicle fuel-dispensing stations, and 
parking garages not classed as Group S, 
Division 4 open parking garages or Group U 
private garages. 

Division 4. Open parking garages. 

Division 5. Aircraft hangars where work is 
hmited to exchange of parts and maintenance 
requiring no open flame or welding, and 
heUstops. 

Group U Occupancies 

Division 1. Private garages, carports, sheds, 
and agricultural buildings. 

Division 2. Fences six (6) feet (1,829 mm) 
high, tanks, and towers. 

OCCUPIED SPACE - An enclosed space intended 
for human activities excluding those spaces intended 
primarily for other purposes such as storage rooms 
and equipment rooms that are only occupied 
occasionally and for short periods of time. 



218.0 



-P- 



PEL (Permissible Exposure Limit) - The maximum 
permitted eight-hour time-weighted average 
concentration of an airborne contaminant. The 
maximum permitted time-weighted average 
exposures to be utilized are those published in 29 
CFR 1910.1000. 

PEX - An acronym for cross-linked polyethylene. 

PIPING - The pipe or tube mains for interconnecting 
the various parts of a system. Piping includes pipe, 
tube, flanges, bolting, gaskets, valves, fittings the 
presstire-containing parts of other components such 
as expansion joints, strainers, and devices that serve 
such purposes as mixing, separating, snubbing, 
distributing, metering, or controlling flow pipe- 
supporting fixtures and structural attachments. 

PLENUM - An air compartment or chamber 
including uninhabited crawl spaces areas above a 
ceiling or below a floor, including air spaces below 
raised floors of computer/ data processing centers or 
attic spaces, to that one or more ducts are cormected 
and that forms part of either the supply-air, return- 
air or exhaust-air system, other than the occupied 
space being conditioned. 

PLUMBING CODE - The Uniform Plumbing Code 
promulgated by the International Association of 
Plumbing and Mechanical Officials, as adopted by 
this jurisdiction. [HCD 1 and HCD 2] Whenever the 
term "Plumbing Code" is used in this code, it shall mean 
the California Plumbiflg Code, Title 24, Part 5. 

PORTABLE COOLING UNIT - A self-contained 
refrigerating system, not over 3 horsepower rating, 
that has been factory assembled and tested, installed 
without supply-air ducts and without cormecting 
any refrigerant-containing parts. This definition shall 
not include an absorption unit. 

PORTABLE EVAPORATIVE COOLER - An evapo- 
rative cooler that discharges the conditioned air 
directly into the conditioned area without the use of 
ducts and can be readily transported from place to 
place without dismantling any portion thereof. 

PORTABLE HEATING APPLIANCE - A heating 
appliance designed for environmental heating that 
may have a self-contained fuel supply and is not 
secured or attached to a building by any means other 
than by a factory-installed power supply cord. 

PORTABLE VENTILATING EQUIPMENT - Venti- 
lating equipment that can be readily transported 
from place to place without dismantling a portion 
thereof and that is not connected to a duct. 

POSITIVE DISPLACEMENT COMPRESSOR - A 

compressor in which increase in pressure is attained 



26 



DEFINITIONS 



218.0-220.0 



by changing the internal volume of the compression 

chamber. 

POWER BOILER PLANT - One or more power steam 

boilers or power hot water boilers and coimecting 

piping and vessels within the same premises. 

PRESSURE, DESIGN - The maximum working 
pressure for which a specific part of a refrigeration 
system is designed. 

PRESSURE, FIELD TEST - A test performed in the 
field to prove system tightness. 

PRESSURE-IMPOSING ELEMENT - A device or 
portion of the equipment used for the purpose of 
increasing the pressure of the refrigerant vapor. 

PRESSURE-LIMITING DEVICE - A pressure- 
responsive mechanism designed to automatically 
stop the operation of the pressure-imposing element 
at a predetermined pressure. 

PRESSURE-RELIEF DEVICE - A pressure-actuated 
valve or rupture member or fusible plug designed to 
automatically relieve excessive pressure. 

PRESSURE TEST - The minimum gauge pressure 
to which a specific system component is subjected 
tmder test condition. 

PRESSURE VESSEL-REFRIGERANT - A 

refrigerant-containing receptacle that is a portion of a 
refrigeration systemi, but shall not include 
evaporators, headers, or piping of certain limited 
size and capacity. 

219.0 -Q- 

QUALIFIED - A competent and capable person or 
company that has met the requirements and training 
for a given field acceptable to the Authority Having 
Jurisdiction. [NFPA 96: 3.3.37] 



220.0 



-R- 



RADIANT HEATER - A heater designed to transfer 
heat primarily by direct radiation. 

RECEIVER, LIQUID - A vessel permanently 
connected to a refrigeration system by inlet arid 
outlet pipes for storage of liquid. 

REFRIGERANT SAFETY CLASSIFICATIONS - 

Made up of a letter (A or B), that indicates the toxicity 
class, followed by a nixmber (1, 2, or 3), that indicates 
the flammability class. Refrigerant blends are 
similarly classified, based on the compositions at their 
worst cases of fractionation, as separately determined 
for toxicity and flammability. In soine cases, the worst 
case of fractionation is the original formulation. 

TOXICITY: Classes A and B signify refrigerants 
with "lower toxicity" and "higher toxicity," 



respectively, based on prescribed measures of 
chronic (long-term, repeated exposures) toxicity. 

FLAMMABILITY: Class 1 indicates refrigerants 
that do not show flame propagation in air when 
tested by prescribed methods at specified 
conditions. Classes 2 and 3 signify refrigerants 
with "lower flammability" and "higher 
flammability," respectively. The distinction 
depends on both the lower flammability limit 
(LFL) and heat of combustion. 

REFRIGERATION MACHINERY ROOM - A space 
designed to safely house compressors and pressure 
vessels. 

REFRIGERATION ROOM or SPACE - A room or 
space in which an evaporator or brine coU is located for 
the piirpose of reducing or controlling the temperature 
within tiie room or space to below 68°F (20°C). 
REFRIGERATION SYSTEM, ABSORPTION - A 
heat-operated closed-refrigeration cycle in which a 
secondary fluid, the absorbent, absorbs a primary 
fluid, the refrigerant, that has been vaporized in the 
evaporator. 

REFRIGERATION SYSTEM, MECHANICAL - A 

combination of interconnected refrigerant-containing 
parts constituting one closed refrigerant circuit in 
which a refrigerant is circulated for the purpose of 
extracting heat and in which a compressor is used 
for compressing the refrigerant vapor. 

REFRIGERATION SYSTEM, SELF-CONTAINED - 

A complete factory-assembled and tested system 
that is shipped in one or more sections and has no 
refrigerant-containing parts that are joined in the 
field by other than companion or block valves. 

RESIDENTIAL BUILDING - A building or portion 
thereof designed or used for human habitation. 

RISER HEAT PIPE - A duct that extends at an angle 
of more than forty-five (45) degrees (0.79 rad) from 
the horizontal. This definition shall not include any 
boot connection. 

ROOM HEATER - A freestanding, nonrecessed, 
environmentar heating appliance installed in the 
space being heated and not coimected to ducts. 

ROOM HEATER, UNVENTED - An unvented, self- 
contained, freestanding, nonrecessed, fuel-gas 
burning appliance for furnishing warm air by 
gravity or fan circulation to the space in which 
installed, directly from the heater without duct 
connection. [NFPA 54: 3.3.55.6] 
ROOM LARGE IN COMPARISON WITH SIZE OF 
EQUIPMENT - A room having a volume of at least 
twelve (12) times the total volume of a furnace or 
air-conditioning appliance and at least sixteen (16) 
times the total volume of a boiler. Total volume of 
the appliance is determined from exterior 



27 



220.0 - 224.0 



2007 CALIFORNIA MECHANICAL CODE 



dimensions and includes fan compartments and 
burner vestibules when used. When the actual 
ceiling height of a room is greater than eight (8) feet 
(2438 nmi), the voltime of the room is figured on the 
basis of a ceiling height of eight (8) feet (2438 mm). 

RUPTURE MEMBER - A pressure-relief device that 
operates by the rupture of a diaphragm within the 
device on a rise to a predetermined pressure. 

221.0 -S- 

SEAM, WELDED. See Joint, Welded. 

SELF-CONTAINED - Having all essential working 
parts, except energy and control connections, so 
contained in a case or framework that they do not 
depend on appliances or fastenings outside of the 
machine. 

SHAFT - An interior space enclosed by walls or 
construction extending through one or more stories 
or basements that connects openings in successive 
floors, or floors and roof, to accommodate elevators, 
dumbwaiters, mechanical equipment, or similar 
devices to transmit light or ventilation air. 

SHAFT ENCLOSURE - The walls or construction 
forming the boundaries of a shaft. 

SHALL - Indicates a mandatory requirement. 

SHOULD - Indicates a recommendation or that 
which is advised but not required. 

SMOKE DETECTOR - An approved device that 
senses visible or invisible particles of combustion. 

STANDARD - A document, the main text of which 
contains only mandatory provisions using the word 
"shall" to indicate requirements and that is in a form 
generally suitable for mandatory reference by another 
standard or code or for adoption into law. 
Nonmandatory provisions shall be located in an 
appendix, footnote, or fine-print note and are not to be 
considered a part of the requirements of a standard. 

STATE BUILDING CODE [For OSHPD 1,2,3& 4] is 

the most recent edition of the California Building Code. 

STATIONARY FUEL CELL POWER PLANT - A 

self-contained package or factory-matched packages 
that constitute an automatically operated assembly 
of integrated systems for generating useful electrical 
energy and recoverable energy that is permanently 
connected and fixed in place. 

STRENGTH, ULTIMATE - The highest stress level 
that the component can tolerate without rupture. 

SYSTEM OUTDOOR AIRFLOW (l/oO - The rate of 
outdoor airflow required at the ventiliation system 
outdoor air intake. 



222.0 -T- 

TRAINED - A person who has become proficient in 
performing a skill reliably and safely through 
instruction and practice /field experience acceptable to 
the Authority Having Jurisdiction. [NFPA 96 3.3.47] 

TESTING AGENCY- [HCD 1 and HCD 2] See 

"Approved Testing Agency". 



223.0 



-U- 



UMC - [HCD 1, HCD 2, OSHPD 1, 2, 3 & 4 and 
SFM] The most recent edition of Uniform Mechanical 
Code published by the International Association of 
Plumbing and Mechanical Officials. 

UMC STANDARDS- [HCD 1, HCD 2 and OSHPD 

1, 2, 3 & 4] The Uniform Mechanical Code Standards 
listed in Appendix A of the most recent edition of Uniform 
Mechanical Code published by International Association 
of Plumbing and Mechanical Officials. 

UNCONFINED SPACE - A room or space having a 
volume equal to at least fifty (50) cubic feet (1.42 m') 
per 1,000 Btu/h (0.293 kW) of the aggregate input 
rating of aU fuel-burning appliances installed in tfiat 
space. Rooms communicating directly with the space 
in which the appliances are installed, through 
openings not furnished with doors, are considered a 
part of the unconfined space. 

UNIT HEATER - A heating appliance designed for 
nonresidential space heating and equipped with an 
integral means for circulation of air. 

UNUSUALLY TIGHT CONSTRUCTION is 

construction where: 

(1) Walls and ceilings exposed to the outside 
atmosphere have a continuous water vapor 
retarder with a rating of one (1) perm or less 
with any openings gasketed or sealed; 

(2) Weatherstripping is on openable windows 
and doors; and 

(3) Caulking or sealants are applied to areas 
such as joints around window and door 
frames, between sole plates and floors, 
between wall-ceiling joints, between wall 
panels, and at penetrations for plumbing, 
electrical, and gas lines and at other 
openings. 

224.0 -V- 

VALVE, PRESSURE-RELIEF - A pressure-achiated 
valve held closed by a spring or other means and 
designed to automatically relieve pressure in excess 
of its setting; also called a safety valve. 

VALVE, STOP - A device in a piping system to shut 
off the flow of the fluid. 



28 



DEFINITIONS 



224.0-226.0 



VALVE, THREE-WAY-TYPE STOP - A manually 
operated valve with one inlet that alternately can 
stop flow to either of two outlets. 

VALVES, COMPANION OR BLOCK - Pairs of 
mating stop valves valving off . sections of 
refrigeration systems and arranged so that these 
sections may be joined before opening these valves 
or separated after closing them. 

VENT - A listed factory-made vent pipe and vent 
fittings for conveying flue gases to the outside 
atmosphere. 

Type B Gas Vent - A factory-made gas vent 
listed by a nationally recognized testing agency 
for venting listed or approved appliances 
equipped to burn only gas. 

Type BW Gas Vent - A factory-made gas vent 
listed by a nationally recognized testing agency 
for venting listed or approved gas-fired vented 
wall furnaces. 

Type L - A venting system consisting of listed 
vent piping and fittings for use with oil-burning 
appliances listed for use with Type L or with 
listed gas appliances. 

VENT CONNECTOR, GAS - That portion of a 
gas-venting system that connects a listed gas 
appliance to a gas vent and is installed within the 
space or area in which the appliance is located. 

VENTED APPLIANCE CATEGORIES 

Category I - An appliance that operates with a 
nonpositive vent static pressure and with a vent 
gas temperature that avoids excessive 
condensate production in the vent. 

Category II - An appliance that operates with a 
non-positive vent static pressure and with a vent 
gas temperature that may cause excessive 
. condensate production in the vent. 

Category III - An appliance that operates with a 
positive vent static pressure and with a yent gas 
temperature that avoids excessive condensate 
production in the vent. 

Category IV - An appliance that operates with a 
positive vent static pressure and with a vent gas 
temperature that may cause .excessive 
condensate production in the vent. 

VENTED DECORATIVE APPLIANCE - A vented 
appliance whose only function is providing an 
aesthetic effect of flames. 

VENTED WALL FURNACE - A vented environmental 
heating appliance designed for incorporation in, or 
permanent attachment to, a wall, floor, ceilirig, or . 



partition and arranged to furnish heated air by gravity 
or by a fan. This definition shall not include floor 
furnaces, unit heaters, and room heaters. 

VENTILATING CEILING - A suspended ceiling 
containing many small apertures through which air, 
at low pressure, is forced downward from an 
overhead plenum. dimensioned by the concealed 
space between the suspended ceiling and the floor or 
roof above. 

VENTILATION SYSTEM - All of that equipment 
intended or installed for the purpose of supplying air 
to, or removing air from, any room or space by 
mechanical means, other than equipment that is a 
portion of an environmental heating, cooling, 
absorption, or evaporative cooling system. 

VENTING COLLAR - The outlet opening of an 
appliance provided for connection of the vent system. 

VENTING SYSTEM - The vent or chimney and its 
connectors, assembled to form a continuous open 
passageway from an appliance to the outside 
atmosphere for the purpose of removing products of 
combustion. This definition also shall include a venting 
assembly that is an integral part of an appliance. 

VENTING SYSTEM-GRAVITY-TYPE ^ A system that 
depends entirely on the heat from the fuel being used 
to provide the energy reqxiired to vent an appliance. 
VENTING SYSTEM-POWER-TYPE - A system 
that depends on a mechanical device to provide a 
positive draft within the venting system. 

VOLUME, INTERNAL GROSS - The volume as 
determined from internal dimensions of the 
container, with no allowance for the volume of the 
internal parts. 



225.0 



-W- 



WALL HEATER. See Vented Wall Furnace. 

WARM AIR FURNACE - An environmental heating 
appliance designed or Arranged to discharge heated 
air through any duct or ducts. This definition shall 
not include a unit heater. 

WATER HEATER or HOT-WATER-HEATING 
BOILER - An appliance designed primarily to 
supply hot water and equipped with automatic 
controls limiting water temperature to a maximum 
of210°F(99°C). 

226.0 -X- 

No definitions. 



29 



227.0 - 228.0 



2007 CALIFORNIA MECHANICAL CODE 



227.0 -Y- 

No definitions. 



228.0 -Z- 

ZEOTROPE - A blend comprising multiple 
components of different volatiles that, when used in 
refrigeration cycles, change volumetric composition 
and saturation temperatures as they evaporate or 
condense at constant pressure. 



30 



CHAPTER 3 

GENERAL REQUIREMENTS 



301 .0 Scope. 

This chapter covers gerieral requirements for 
heating, ventilating, air-conditioning, refrigeration, 
miscellaneous heat-producing, and energy-utilizing 
equipment. Such equipment shall conform to the 
requirements of this code. 

Equipment shall not be installed or altered in 
violation of this code, nor shall the fuel input rate to 
equipment be increased in excess of the approved 
Btu/h (kW) rating at the altitude where it is being used. 

Defective material or parts shall be replaced in 
such a manner as not to invalidate any approval. 

302.0 Approval. 

302.1 How Obtained. Each appliance shall be 
approved by the Authority Having Jurisdiction for 
safe use or comply with applicable nationally 
recogiuzed standards as evidenced by the listing and 
label of an approved agency. A list of accepted 
standards is included in Chapter 17. 

302.2 Complying Design of Equipment. Installers 
shall furnish satisfactory evidence that the appliance 
is constructed in conformity with the requirements 
of this code. The permanently attached label of an 
approved agency may be accepted as such evidence. 

302.3 Oil-Burning Appliances. The tank, piping, 
and valves for appliances burning oil shall be 
installed in accordance with the requirements of 
NFPA 31, Standard for the Installation of Oil- 
Burning Equipment. 

303.0 Connecting Gas Equipment. 

303.1 Gas utilization equipment shall be connected 
to the building piping in compliance with Section 
1312.4 by one of the following: 

(1) Rigid metallic pipe and fittings. 

(2) Semi-rigid metallic tubing and metallic 
fittings. Aluminum alloy tubing shall not be 
used in exterior locations. 

(3) Listed connectors used in accordance with 
the terms of their listing that are completely 
in the same room as the equipment. 

(4) Listed gas hose connectors in accordance 
with Section 303.2. 

(5) Gas-fired food service (commercial cooking) 
equipment listed for use with casters or 
otherwise subject to movement for cleaning. 



and other large and heavy gas utilization 
equipment that can be moved, shall be 
connected in accordance with the connector 
manufacturer's installation instructions 
using a listed appliance connector 
complying with ANSI Z21.69, Standard for 
Connectors for Movable Gas Appliances. 
(6) In Sections 303.1(2), (3), and (5), the connector or 
tubing shall be installed so as to be 
protected against physical and thermal 
damage. Aluminum alloy tubing and con- 
nectors shall be coated to protect against 
external corrosion where they are in contact 
with masonry, plaster, or insulation or are 
subject to repeated wettings by such liquids 
as water (except rainwater), detergents, or 
sewage. 

303.2 Use of Gas Hose Connectors. Listed gas 
hose connectors shall be used in accordance with the 
terms of their listing and as follows: 

(A) Indoor. Indoor gas hose connectors shall be 
permitted to be used with laboratory, shop, 
or ironing equipment that requires mobility 
during operation. An equipment shutoff 
valve shall be installed where the connector 
is attached to the building piping. The 
connector shall be of mirumum length and 
shall not exceed 6 feet. (1.8 m). The connector 
shall not be concealed and shall not extend 
from one room to another or pass through 
wall partitions, ceilings, or floors. 

(B) Outdoor. Outdoor gas hose connectors shall 
be permitted to be used to connect portable 
outdoor gas-fired equipment. An equipment 
shutoff valve, a listed quick-disconnect 
device, or a listed gas convenience outlet 
shall be installed where the connector is 
attached to the supply piping and in such a 
manner so as to prevent the accumulation of 
water or foreign matter. This connection 
shall only be made in the outdoor area 
where the equipment is to be used. 

303.3 Connection of Portable and Mobile Industrial 
Gas Equipment. 

(A) Portable industrial gas utilization equipment 
or equipment requiring mobility or subject 
to vibration shall be permitted to be 
connected to the building gas piping system 
by the use of flexible hose suitable and safe 
for the conditions under which it can be used. 



31 



303.3 - 305.0 



2007 CALIFORNIA MECHANICAL CODE 



(B) Industrial gas utilization equipment requi- 
ring mobility shall be permitted to be 
connected to the rigid piping by the use of 
swivel joints or couplings that are suitable 
for the service required. Where swivel joints 
or couplings are used, only the minimum 
number required shall be installed. 

(C) Industrial gas utilization equipment subject 
to vibration shall be permitted to be 
connected to the building piping system by 
the use of all metal flexible connectors 
suitable for the service required. 

(D) Where flexible connections are used, they 
shall be of the minimum practical length 
and shall not extend from one room to 
another or pass through any walls, 
partitions, ceilings, or floors. Flexible 
connections shall not be used in a concealed 
location. They shall be protected against 
physical or thermal damage and shall be 
provided with gas shutoff valves in readily 
accessible locations in rigid piping upstream 
from the flexible connections. [NFPA 
54:8.5.1, 8.5.2, 8.5.3] 

304.0 Installation. 

304.1 Listed Appliances. Except as otherwise 
provided in the code, the installation of appliances 
regulated by this code shall conform to the 
conditions of listing. The appliance installer shall 
leave the manufacturer's installation and operating 
instructions attached to the appUance. Clearances of 
listed appliances from combustible materials shall be 
as specified in the listing or on the rating plate. 

304.2 Room Large in Comparison to Size of 
Equipment. Central-heating furnaces not listed for 
closet or alcove installation shall be installed in a 
room or space having a volume at least twelve (12) 
times the total volume of the furnace; central-heating 
boilers not listed for closet or alcove installation shall 
be installed in a room or space having a volume 
sixteen (16 ) times the volume of the boiler. 

Exceptions: 

(1) The installation clearances for furnaces and 
boilers in rooms not large in comparison 
with the size of the equipment shall be as 
specified in the appliance listing regardless 
of whether the enclosure is of combustible 
or noncombustible materials and shall not 
be reduced by the protection methods 
described in Table 3-2 or any other method. 

(2) [For OSHPD 1,2&4]A reduction boiler room 
sizing up to 25 percent will be acceptable with 



forced draft combustible blowers and approved 
ventilation of the boiler room. In no case shall 
boiler room volume or clearances he reduced 
below those required by the conditions of the 
boiler listing. The boiler and the boiler room 
ventilation system, including fans, controls and 
damper motors shall he on emergency power 
when required by Section 316. The ventilation 
system shall either operate continuously, or, if 
interlocked with the boiler(s), it shall not 
interfere with the proper boiler operation. 

If the ceiling height of the room or space is 
greater than eight (8) feet (2,438 mm), the volume 
shall be calculated on the basis of an eight (8) foot 
(2,438 Tom) height. 

304.3 Unlisted Appliances. Unlisted appliances shall 
be installed with the standard clearances from 
combustible construction specified in Table 3-1. 
Unlisted appliances may have the standard clearances 
of Table 3-1 reduced by employing the forms of 
protection specified in Table 3-2. Forms of protection 
specified in Table 3-2 may be utilized to reduce 
clearances to combustible construction for all 
applicable appliances. 

304.4 Anchorage of Appliances. Appliances 
designed to be fixed in position shall be securely 
fastened in place. Supports for appliances shall be 
designed and constructed to sustain vertical and 
horizontal loads within the stress limitations 
specified in the Building Code. 

304.5 Identification of Equipment. When more than 
one heating, cooling, ventilating, or refrigerating 
system is installed on the roof of a btiilding or within 
a buUding, it shall be permanently identified as to the 
area or space served by the equipment. 

304.6 Liquefied Petroleum Gas Facilities. 

Containers, container valves regulating equipment, 
and appurtenances for the storage and supply of 
liquefied petroleum gas shall be installed in 
accordance with the California Fire Code. 

304.7 Liquefied Petroleum Gas Appliances. 
[HCD 1 and HCD 2] Liquefied petroleum gas-hurning 
appliances shall not he installed in a pit, basement or 
similar location where heavier-than-air gas might collect. 
Appliances so fueled shall not be installed in an above- 
grade under-floor space or basement unless such location 
is provided with an approved means for removal of 
unburned gas. 

305.0 Access. 

Appliances shall be accessible for inspection, service, 
repair, and replacement without removing permanent 
construction. 

Unless otherwise specified, not less than thirty 
(30) inches (762 mm) in depth, width, and height of 



32 



GENERAL REQUIREMENTS 



305.0 - 307.2 



a 



working space and platform shall be provided to 
service the appliance. 

Exception: Unit heaters and room heaters may be 
installed with an eighteen (18) inch (457 mm) 
minimum depth working space. A platform shall 
not be reqiured for unit heaters or room heaters. 
The operating instructions shall be attached to 
the appliance where they can be read easUy. 

305.1 Accessibility for Service. All gas utilization 
equipment shall be located with respect to building 
construction and other equipment so as to permit 
access to the gas utilization equipment. Sufficient 
clearance shall be maintained to permit cleariing of 
heating surfaces; the replacement of filters, blowers, 
motors, burners, controls, and vent coimections; the 
lubrication of moving parts where necessary; the 
adjustment and cleaning of burners and pilots; and 
the proper functioning of explosion vents, if provided. 
For attic installation, the passageway and servicing 
area adjacent to the equipment shall be floored. 

306.0 Automatic Control Devices. 

Heating appliances shall be equipped with a listed 
device or devices that will shut off the fuel supply to 
the main burner or burners in the event of pilot or 
ignition failure. In addition, liquefied petroleum 
gas-air-burning heating appliances shall be equipped 
with a listed automatic device or devices that will 
shut off the flow of gas to the pilot in the event of 
ignition failure. 

Exception: The listed shutoff devices shall not be 
required on range or cooking tops, log lighters, 
lights, or other open-biirner manually operated 
appliances, or listed appliances not requiring 
such devices and specific industrial appliances as 
approved by the Authority Having Jurisdiction. 

Heating appliances whose manual fuel controls 
are not readily accessible from the main portion of 
the building being heated shall be equipped with 
remote controls. 

Forced-air and gravity-type warm-air furnaces 
shall be equipped with a listed air outlet temperature 
limit control that cannot be set for temperatures 
higher than 250°F (121°C). Such controls shall be 
located in the bonnet or plenum, within two (2) feet 
(610 mm) of the discharge side of the heating 
element of gravity furnaces or in accordance with the 
conditions of listing. 

Electric duct heaters shall be equipped with an 
approved automatic reset air outlet temperature limit 
control that wiU limit the outlet air temperature to not 
more than 2G0°F (93°C). The electric elements of the 
heater shaU be equipped with fusible links or a manual 



reset temperature Umit control that wiU prevent ouflet 
air temperature in excess of 250°F (121 °C). 

307.0 Labeling. 

307.1 Fuel-Burning Appliances. Fuel-burning 
heating appUances shaU bear a permanent and legible 
factory-applied nameplate on which shaU appear: 

307.1 .1 The manufacturer's name. 

307.1.2 The approved fuel input rating of the 
appliance, expressed in Btu/h (W). 

307.1 .3 The model and serial number. 

307.1.4 Instructions for the lighting, operation, 
and shutdown of the appliance. 

307.1.5 The type of fuel approved for use with 
the appliance. 

307.1.6 The symbol of an approved agency 
certifying compliance of the equipment with 
recognized standards. 

307.1.7 Required clearances from combustible 
surfaces on which or adjacent to which it may be 
mounted. 

307.2 Electric Heating Appliances. Electric 
heating appliances shall bear a permanent and 
legible factory-applied nameplate on which shall 
appear: 

307.2.1 The name or trademark of the 
manufacturer. 

307.2.2 The catalog (model) number or 
equivalent. 

307.2.3 The electrical rating in volts, amperes 
(or watts), and, for other than single phase, the 
number of phases. 

In addition, the appliance shall be 
permanently and legibly marked at the factory 
with: 

307.2.4 The output rating in Btu/h or kW. 

307.2.5 The electrical rating in volts, amperes, 
or watts of each field-replaceable electrical 
component. 

307.2.6 The symbol of an approved agency 
certifying compliance of equipment with 
recognized standards. 

307.2.7 Required clearances from, combustible 
surfaces on which or adjacent to which it may be 
mounted. 

Also, the appliance shall be accompanied by 
clear and complete installation instructions, 
including required clearances from combustibles 
other than mounting or adjacent surfaces, and 
temperature rating of field-installed wiring 
connections if over 140°F (60°C). 



33 



307.3-310.3 



2007 CALIFORNIA MECHANICAL CODE 



307.3 Heat Pump Appliances. Heat pumps shall 
bear a permanent and legible factory-applied 
nameplate on which shall appear: 

307.3.1 The name or trademark of the manufacturer. 

307.3.2 The catalog model nomenclature. 

307.3.3 The amount and type of refrigerant. 

307.3.4 The factory test pressures or pressures 
applied. 

307.3.5 The symbol of an approved agency 
certifying compliance of the equipment with 
recognized standards. 

308.0 Location. 

308.1 Protection Against Damage. Appliances 
installed in garages, warehouses, or other areas 
subject to mechanical damage shall be guarded 
against such damage by being installed behind 
protective barriers or by being elevated or located 
out of the normal path of vehicles. 

Heating and cooling equipment located in a 
garage and that generates a glow, spark, or flame 
capable of igniting flammable vapors shall be 
installed with the pilots and burners or heating 
elements and switches at least eighteen (18) inches 
(457 mm) above the floor level. 

Where such appliances installed within a garage 
are enclosed in a separate, approved compartment 
having access only from outside of the garage, such 
appliances may be installed at floor level, provided 
the required combustion air is taken from, and 
discharged to the exterior of the garage. 

Heating equipment located in rooms where 
cellulose nitrate plastic is stored or processed shall 
comply with the Fire Code. 

308.2 Protection Against Flood Damage. For 

buildings located in flood hazard areas, heating, 
ventilating, air-conditioning, refrigeration, 
miscellaneous heat-producing, and energy-utilizing 
equipment and appliances shall be elevated at or 
above the design flood elevation. 

Exception: Equipment and appliances are 
permitted to be located below the design flood 
elevation provided that they are designed and 
installed to prevent water from entering or 
accumulating within the components and to 
resist hydrostatic and hydrodynamic loads and 
stresses, including the effects of buoyancy, 
during the occurrence of flooding to the design 
flood elevation in compliance with the flood- 
resistant construction requirements of the 
Building Code. 

308.2.1 Walls Below Buildings in Flood 
Hazard Areas Subject to High Velocity Wave 
Action. In flood hazard areas subject to high 



velocity wave action, equipment and appliances, 
including piping, shall not be mounted on or 
penetrate walls intended to break away under 
flood loads. 

308.2.2 Air Exhaust and Intake Openings. 

Outside air exhaust openings and air intake 
openings shall be located at or above the design 
flood elevation. 

309.0 Electrical Connections. 

Equipment regulated by this code requiring electrical 
connections of more than fifty (50) volts shall have a 
positive means of disconnect adjacent to and in sight 
from the equipment served. A 120 volt receptacle 
shall be located within twenty-five (25) feet (7,620 
mm) of the equipment for service and maintenance 
purposes. The receptacle need not be located on the 
same level as the equipment. Low-voltage wiring of 
fifty (50) volts or less within a structure shall be 
installed in a manner to prevent physical damage. 

310.0 Condensate Wastes and Control. 

310.1 Condensate Disposal. Condensate from air 
washers, air-cooling coils, fuel-burning condensing 
appliances, and the overflow from evaporative 
coolers and similar water-supplied equipment or 
similar air-conditioning equipment shall be collected 
and discharged to an approved plumbing fixture or 
disposal area. If discharged into the drainage system, 
equipment shall drain by means of an indirect waste 
pipe. The waste pipe shall have a slope of not less 
than 1/8 inch per foot (10.5 mm/m) or 1 percent slope 
and shaU be of approved corrosion-resistant material 
not smaller than the outlet size as required in either 
Section 310.3 or 310.4 for air-cooling coils or 
condensing fuel-burning appliances, respectively. 
Condensate or wastewater shall not drain over a 
public way. 

310.2 Condensate Control. When a cooling coil or 
cooling unit is located in an attic or furred space 
where damage may result from condensate 
overflow, an additional watertight pan of corrosion- 
resistant metal shaU be installed beneath the cooling 
coil or unit top to catch the overflow condensate due 
to a clogged primary condensate drain, or one pan 
with a standing overflow and a separate secondary 
drain may be provided in lieu of the secondary drain 
pan. The additional pan or the standing overflow 
shall be provided with a drain pipe, minimum 3/4 
inch (19.1 mm) nominal pipe size, discharging at a 
point that can be readily observed. 

This requirement is in addition to the 
requirements in Sections 310.3 and 310.4. 

310.3 Condensate Waste Sizing. Condensate waste 
pipes from air-cooling coils shall be sized in 
accordance with equipment capacity as follows: 



34 



GENERAL REQUIREMENTS 



310.2-314.2 



Equipment Capacity in 


IVIinimum Condensate 




Pipe Diameter 


ions or 








Refrigeration 


(kW) 


Inches 


(mm) 


Up to 20 


(Up to 70.34) 


3/4 


(20) 


21-40 


(73.85-140.67) 


1 


(25) 


41-90 


(144.19-316.6) 


1-1/4 


(32) 


91-125 


(320.03^39.6) 


1-1/2 


(40) 


126-250 


(443.12-879.2) 


2 


(50) 



The size of condensate waste pipes may be for 
one unit or a combination of units, or as 
recommended by the manufacturer. The capacity of 
waste pipes assumes a 1/8 inch per foot (10.5 
mm/m) or 1 percent slope, with the pipe rurming 
three-quarters full at the following conditions: 
Outside Air -20% Room Air -80% 

DB WB DB WB 

90T 73°F 75T 62.5T 

(32°C) (23°C) (24°C) (17°C) 

Condensate drain sizing for other slopes or other 
conditions shall be approved by the Authority 
Having Jurisdiction. 

310.4 Fuel-Burning Appliance Condensate 
Drains. Condensate drain lines from individual 
fuel-burning condensing appliances shall be sized 
according to the manufacturer's recommendations. 
Condensate drain lines serving more than one 
appliance shall be approved by the Authority 
Having Jurisdiction prior to installation. 

310.5 Plastic Fittings. Female PVC screwed fittings 
shall be used with plastic male fittings and plastic 
male threads only. 

311.0 Personnel Protection. 

A suitable and substantial metal guard shall be 
provided around exposed fljrwheels, fans, pulleys, 
belts, and moving machinery that are portions of a 
heating, ventilating, or refrigerating system. 

312.0 Air Filters. 

312.1 Air filters shall be installed in a heating, 
cooling or makeup air system. Such filters shall 
comply with the standard. Air Filter Units, Test 
Performance of, that is referenced in Chapter 17, as 
Class I or n filters. 

Exception: Systems serving single guest rooms 
or dwelling imits shall not require a listed filter. 

313.0 Scope 

313.1 Applicability. This- -part is ap-plicahle to health 



facilities regulated by OSHPD. (See Adoption Tables for 
application for specific sections.) 

Note: This section has no corresponding provisions 
in the UMC. For the scope and authority of each state 
agency, refer to Chapter 1. 

313.2 Services/Systems and Utilities. Refer to Section 
1224.4.1 California Building Code. 

314.0 Steam and Hot-Water Systems 

314.1 Requirements for Hospitals and Optional 
Services Provided In Correctional Treatment 
Centers. [For OSHPD 1 & 4] 

314.1.1 Boilers shall have the capacity, based upon 
the rest ratings published by the Hydronics Institute 
or another acceptable national standard to supply the 
normal operating requirements of all connected 
systems and equipment. 

314. 1.2 A minimum of two boilers shall he provided. 
The arrangement of boilers shall he based on the 
capacity and capability of a boiler or boilers to operate 
all systems during-periods of breakdown or 
maintenance of any one boiler. 

314.1.3 Boiler systems providing space heating shall 
be designed to maintain a minimum temperature of 
60 °F (15.6°C) in general patient areas and the 
temperatures specified in Table 315 for sensitive areas 
during periods of breakdown or maintenance of any 
one boiler. Winter design temperature shall be based 
on the Median of Extremes shown by the 1982 
ASHRAE Climactic Data for Region X. 

314.1.4 Boiler feed pumps, condensate return 
pumps, fuel oil pumps and heating circulating pumps 
shall be connected and installed to provide standby 
service in the event of pump failure. Installation of 
duplex pumps or provision of a spare pump will meet 
this requirement. 

314.1.5 At least two sources of heat (e.g. two pieces 
of equipment) shall be provided for supplying 
essential services such as sterilizers, hot water for 
dishwashing, and domestic hot water for minimum 
patient service, such as handwashing and baths. 
Booster heaters for dishwashing providing 125°F to 
180 °F (52°C to 82 °C) water may be counted as the 
second source of heat for that service. 

314.2 Requirements for Skilled Nursing, 
Intermediate Care Facilities and Basic Services 
Provided in Correctional Treatment Centers. [For 
OSHPD 2 & 4] 

314.2.1 Boilers, if provided, shall accommodate 
Section 314.1. 

314.2.2 Two or more interconnected water heaters 
are an acceptable means to provide two sources of 
heat for hot water. See Section 314.1.5. 



35 



315.0-316.5 



2007 CALIFORNIA MECHANICAL CODE 



315.0 Air Conditioning and Heating Systems 

315.1 Requirements for Hospitals and Optional 
Services Provided in Correctional Treatment 
Centers. [For OSHPD 1 & 4] 

315.1.1 The systems shall be designed to provide the 
temperatures and humidities for sensitive areas or 
rooms shown in Table 315. 

315.1.2 Individual temperature and humidity 
controls shall be provided for each designated 
sensitive area or room. 

315.1.3 Dew-point control with individual 
overriding room humidistat will be acceptable as a 
substitute when justification is provided. 

315.1.4 Rooms controlled by the same thermostat 
with similar exposure, function and requirements 
may have humidity control with zone humidifier 
where designs are specifically approved by the 
enforcing agency. 

315.1.5 Heating systems shall have heating capacity 
to provide the minimum temperatures and humidities 
in Table 315, in all areas occupied by patients or 
personnel under normal conditions of hospital 
operation. 

31 5.1. 6 For all other occupied areas, heating systems 
shall be designated to provide 70°F to 75°F (21.1 °C to 
23.9°C) temperatures under winter design 
conditions. The systems shall be thermostatically 
controlled with appropriate zoning to achieve the 
above conditions. 

315.1.7 In all patient-occupied areas cooling systems 
shall be designed to provide 75°F (23.9°C) maximum 
based on the 0.5 percent summer design dry bulb 
temperatures shown by the 1982, ASHRAE Climate 
Data for Region X. The heating and cooling system 
should be thermostatically controlled with 
appropriate zoning to achieve the above conditions. 

315.2 Requirements for Sidlled Nursing, 
Intermediate Care Facilities and Basic Services 
Provided in Correctional Treatment Centers. [For 
OSHPD 2 & 4] 

315.2.1 Systems shall accommodate the provisions of 
Section 315.1.6 through 315.1.7. 

315.2.2 Where air conditioning is provided, the 
system shall be thermostatically controlled in one or 
more zones, 

315.3 Requirements for Outpatient Facilities and 
Licensed Clinics. [For OSHPD 3] 

315.3.1 The system shall be designed to provide the 
temperature and humidities for sensitive areas for 
rooms shown in Table 315. 



Table 315 -Heating and Cooling 





Temperature 


Relative 




Range''' 


Humidity" 


Area or Room Designation 


T 


Percent 


Operating room 


6S-73 


30-60 


Cystoscopy 


68-73 


30-60 


Cardiac cath lab 


70-75 


30-60 


Delivery room 


68-73 


30-60 


Recovery room 


70 


30-60 


Newborn nursery 


75 


30-60 


Intensive-care newborn nursery 


75-80 


30-60 


Intensive care 


70-75 


30-60 



1 Thermostats and humidistat shall be either locally resetable and of the non- 
locking type or remotely resetable and of the locking type. 

2 Where temperature ranges are indicated, the system shall be capable of 
maintaining the rooms at any point within the range. A single figure-indicates 
a heating or cooling capacity of at least the indicated temperature. 
Temperatures different than those shown will be allowed when approved by the 
Authority Having Jurisdiction. 

3 The ranges listed are the minimum and maximum limits where control is 
specifically needed. 

316.0 Essential Mechanical Provisions [For 
OSHPD 1, 2, 3(surgical clinics only) & 4] During 
periods of power outages emergency electrical power shall 
be provided for the following equipment: 

316.1 (Does not apply to OSHPD 3 surgical clinic.) All 
heating equipment necessary to maintain a minimum 
temperature of60°F (15.6°) in patient areas which are not 
specified in Table 315. 

316.2 All heating equipment necessary to maintain the 
minimum temperatures for sensitive areas as specified in 
Table 315. 

316.3 Equipment necessary for humidification of the 
areas listed in Table 315. 

316.4 All supply, return and exhaust fans required to 
maintain the positive and negative air balances as required 
in Table 4-A. 

316.5 All control components and control systems 
necessary for the normal operation of equipment required 
to have emergency electrical power. 



36 



GENERAL REQUIREMENTS 



Table 3-1 





TABLE 3-1 














Standard Installation Cle 


arances in Inches for Unlisted Heat-Produci 

See Section 304.0. 


ng Appliances 








In X 25.4= mm 






APPLIANCE 




FROM TOP 








RESIDENTIAL-TYPE APPLIANCES 






AND SIDES OF 












ABOVE TOP 


WARM-AIR 
BONNET OR 


FROM 


FROM 


FROM 






OF CASING OF 




FUEL 


APPLIANCE 


PLENUM 


FRONT' 


BACK 


SIDES 


BOILERS AND WATER HEATERS" 














Steam Boilers— 15 psi (103.4 kPa) 


Automatic Oil or 












Water Bollers-250°F (121°C) 


Comb. Gas-Oil 


6 




24 


6 


6 


Water Heaters-200°F (93°C) 


Automatic Gas 


6 




18 


6 


6 


All Water Walled or Jacketed 


Solid 


6 




48 


6 


6 


FURNACES-CENTRAL; OR HEATERS"- 


Automatic Oil or 












ELECTRIC CENTRAL WARM-AIR FURNACES 


Comb. Gas-Oil 


6= 


6= 


24 


6 


6 


Gravity, Upflow, Downflow, Horizontal and 


Automatic Gas 


6^ . 


6^ 


18 


6 


6 


Duct Warm-Air-250°F (12rC) max. 


Solid 


18^ 


18= 


48 


18 


18 




Electric 


6^ 


6^ 


18 


6 


6 


FURNACES-FLOOR 


Automatic Oil or 












For IVlounting in Combustible Floors 


Comb. Gas-Oil 


36 




12 


12 


12 




Automatic Gas 


36 




12 


12 


12 


HEAT EXCHANGERS 














Steam-15 psi (103.4 kPa) max. 




1 


1 


1 


1 


1 


Hot Water- 250°F (121°C) max. 














ROOM HEATERS' 


Oil or Solid 


36 




24 


12 


12 


Circulating Type 


Gas 


36 




24 


12 


12 


Radiant or Other Type : 


Oil or Solid 


36 




36 


36 


36 




Gas 


36 




36 


18 


18 




Gas with double metal 














or ceramic back 


36 




36 


12 


18 


Fireplace Stove 


Solid 


48= 




54 


48= 


48= 


RADIATORS 














Steam or Hot Water" 




36 




6 


6 


6 


RANGES-COOKING STOVES 












Firing 
Side 


iP£ 




Oil 


30' 






g 


24 


18 




Gas 


30' 






6 


6 


6 




Solid Clay-Lined 
















Firepot 


30' 






24 


24 


18 




Solid Unlined 
















Firepot 
Electric 


30' 
30' 






36 
6 


36 


18 


6 


INCINERATORS 














Domestic Types 




36= 




48 


36 


. 36 






APPLIANCE 




FROM TOP 








COMIWERCIAL INDUSTRIAL-TYPE APPLIANCES 






AND SIDES OF 








ANY AND ALL PHYSICAL SIZES EXCEPT AS NC 


TED" 


ABOVE TOP 


WARM-AIR 












OF CASING OR 


BONNET OR 


■FROM 


FROM 


FROM 




FUEL 


APPLIANCE 


PLENUM 


FRONT' 


BACK" 


SIDES' 


BOILERS AND WATER HEATERS 














100 cu. ft. (2.832 m=) or less 














Steam, any pressure 


All Fuels 


18 




48 


18 


18 


50 psi (345 kPa) or less 














Any size 


All Fuels 


18 




48 


18 


18 


UNIT HEATERS 


Steam or Hot 












Floor Mounted or Suspended— Any Size 


Water 


1 






1 


. 1 


Suspended— 100 cu. ft. (2.832 m=) or less 


Oil or Comb. 














Gas-Oil 


6 




24 


18 


18 


Suspended— 100 cu. ft. (2.832 m") or less 


Gas 


6 . 




18 


18 


18 


Suspended— Over 100 cu. ft. (2.832 m=) 


All Fuels 


18 




48 


18 


18 


Floor Mounted— Any Size 


Ail Fuels 


18 




48 


18 


18 


RANGES-RESTAURANT-TYPE 














Floor Mounted 


All Fuels 


48 




48 


18 


18 


OTHER LOW-HEAT INDUSTRIAL APPLIANCES 














Floor Mounted or Suspended 


All Fuels 


18 


18 


48 


18 


18 



37 



Table 3-1 



2007 CALIFORNIA MECHANICAL CODE 



TABLE 3-1 (Continued) 

Standard Installation Clearances in Inches for Unlisted Heat-Producing Appliances 





)TED" 


APPLIANCE 


COMMERCIAL INDUSTRIAL-TYPE APPLIANCES 
ANY AND ALL PHYSICAL SIZES EXCEPT AS NC 


ABOVE TOP 

OF CASING OR 

APPLIANCE 


FROM TOP 

AND SIDES OF 

WARM-AIR 

BONNET OR 

PLENUM 


FROM 
FRONT' 


FROM 
BACK'" 


FROM 
SIDES'" 




FUEL 


BOILERS AND WATER HEATERS 
Over 50 psi (345 kPa) 
OverlOOcu.ft. f2832mn 


All Fuels 


48 




96 


36 


36 


OTHER MEDIUM-HEAT INDUSTRIAL 
APPLIANCES 
All Sizes 


All Fuels 


48 


36 


96 


36 


36 


INCINERATORS 
All Sizes 




48 




96 


36 


36 


INDUSTRIAL-TYPE HIGH-HEAT APPLIANCES 
HIGH-HEAT INDUSTRIAL APPLIANCES 
All Sizes 


All Fuels 


180 




360 


120 


120 



Footnotes for Table 3-1 

"I Ttie minimum dimension shall be that necessary for servicing the appliance, including access for cleaning and normal care, tube removal, etc. 

2 For a listed oil, combination gas-oil, gas, or electric furnace, this dimension may be two (2) inches (51 mm) if the furnace limit control cannot be 
set higher than 250° F (121°C), or this dimension may be one (1) inch (25.4 mm) if the limit control cannot be set higher than 200° F (93°C), or 
the appliance shall be marked to indicate that the outlet air temperature cannot exceed 200° F (93°C). 

3 The dimension may be six (6) inches (152 mm) for an automatically stoker-fired forced-warm-air furnace equipped with 250° F (121°C) limit 
control and with barometric draft control operated by draft intensity and permanently set to limit draft to a maximum intensity of 0.13 inch (3.3 
mm) water gauge. 

''■ Unlisted appliances shall be installed on noncombustible floors and may be installed on protected combustible floors. Heating appliances 
approved for installation on protected combustible flooring shall be so constructed that flame and hot gases do not come in contact with the 
appliance base. Protection for combustible floors shall consist of four (4) inch (102 mm) hollow masonry covered with sheet metal at least 
0.021 inch (0.53 mm) thick (No. 24 manufacturer's standard gauge). Masonry shall be permanently fastened in place in an approved manner 
with the ends unsealed and joints matched so as to provide free circulation of air through the masonry. Floor protection shall extend twelve (12) 
inches (305 mm) at the sides and rear of the appliance, except that at least eighteen (18) inches (457 mm) shall be required on the 
appliance-opening side or sides measured horizontally from the edges of the opening. 

^ The forty-eight (48) inch (1219 mm) clearance may be reduced to 36 inches (914 mm) when protection equivalent to that provided by (a)-(g) of 
Table 3-2 is applied to the combustible construction. 

^ Steam pipes and hot water heating pipes shall be installed with a clearance of at least one (1 ) inch (25 mm) to all combustible construction or 
material, except that at the points where pipes carrying steam at not over fifteen (15) pounds gauge pressure (103.4 kPa) or hot water that 
emerge from a floor, wall, or ceiling, the clearance at the opening through the finish floorboards or wall-ceiling boards may be reduced to not 
less than one-half (1/2) inch (12.7 mm). Each such opening shall be covered with a plate of noncombustible material. 
Such pipes passing through stock shelving shall be covered with not less than one (1) inch (25.4 mm) of approved insulation. 
Wood boxes or casings enclosing uninsulated steam or hot water heating pipes or wooden covers to recesses in walls in which such 
uninsulated pipes are placed shall be lined with metal or Insulating millboard. 

Where the temperature of the boiler piping does not exceed 1 60° F (71 °C), the provisions of this table shall not apply. 

Coverings or insulation used on steam or hot water pipes shall be of material suitable for the operating temperature of the system. The 
insulation or jackets shall be of noncombustible materials, or the insulation or jackets and lap-seal adhesives shall be tested as a composite 
product. Such composite product shall have a flame-spread rating of not more than twenty-five (25) and a smoke-developed rating not to 
exceed fifty (50) when tested in accordance with UBC Standard No. 42-1 . 

^ To combustible material or metal cabinets. If the underside of such combustible material or metal cabinet is protected with insulating millboard 
at least one-quarter (1/4) inch (8.4 mm) thick covered with sheet metal of not less than 0.013 inch (0.33 mm) (No. 28 gauge), the distance may 
be reduced to twenty-four (24) inches (610 mm). 

S Clearance above charging door shall be at least forty-eight (48) inches (1 ,21 9 mm). 

^ If the appliance is encased in brick, the eighteen (18) inch (457 mm) clearance above and at the sides and rear may be reduced to twelve (12) 
inches (305 mm). 

'"'if the appliance is encased in brick, the clearance above may be reduced to thirty-six (36) inches (914 mm) and at the sides and rear may be 
reduced to eighteen (18) inches (457 mm). 

"• "• A central heating boiler or furnace shall be installed in accordance with the manufacturer's instructions and shall be installed on a floor of 
noncombustible construction with noncombustible flooring and surface finish and with no combustible material against the underside thereof, or 
on fire-resistive slabs or arches having no combustible material against the underside thereof. 
Exception No. 1 : Appliances listed for installation on a combustible floor. 
Exception No. 2: Installation on a floor protected in an approved manner. [NFPA 54:9.3.3] 



38 



GENERAL REQUIREMENTS 



Table 3-2 - Figure 3-1 



^ 



TABLE 3-2 
Clearances, in Inches, with Specified Forms of Protection^'^ 



in X 25.4 = mm 



TYPE OF PROTECTION 
Applied to the Combustible Material Unless 








Where the Standard Clearance ir 


Table 3-1 with No Protection Is: 




36 inches 


18 Inches 


12 Inches 


9 inches 


6 inches 


























Otherwise Specified and Covering All 






Chimney 






Chimney 






Chimney 






Chimney 


Surfaces within the Distance Specified as 




Sides 


or Vent 




Sides 


or Vent 




Sides 


or Vent 




Sides 


or Vent 


the Required Clearance with No Protection 




and 


Con- 




and 


Con- 




and 


Con- 




and 


Con- 


(Thicknesses Are Minimum) 


Above 


Rear 


nector 


Above 


Rear 


nector 


Above 


Rear 


nector 


Above 


Rear 


nector 


(a) 1/4" insulating millboard spaced out 1"= 


30 


18 


30 


15 


9 


12 


9 


6 


6 


3 


2 


3 


(b) 0.01 3" (No. 28 manufacturer's standard 


























gauge) steel sheet on 1/4" insulating 


























millboard 


24 


18 


24 


12 


9 


12 


9 


6 


4 


3 


2 


2 


(c) 0.013" (No. 28 manufacturer's standard 


























gauge) steel sheet spaced out 1 "' 


18 


12 


18 


9 


6 


9 


6 


4 


4 


2 


2 


2 


(d) 0.01 3" (No. 28 manufacturer's standard 


























gauge) steel sheet on 1/8" insulating 


























millboard spaced out 1"= 


18 


12 


18 


9 


6 


9 


6 


4 


4 


2 


2 


2 


(e) 1-1/2" insulating cement covering on heating 


























appliance 


18 


12 


36 


9 


6 


18 


6 


4 


9 


2 


1 


6 


(f) 1/4" insulating millboard on 1" mineral fiber 


























batts reinforced with wire mesh or equivalent 


18 


12 


18 


6 


6 


6 


4 


4 


4 


2 


2 


2 


(g)0.027" (No. 22 manufacturer's standard 


























gauge) steel sheet on 1 " mineral fiber batts 


























reinforced with wire or equivalent 


18 


12 


12 


4 


3 


3 


2 


2 


2 


2 


2 


2 


(h)1/4" insulating millboard 


36 


36 


36 


18 


18 


18 


12 


12 


9 


4 


4 


4 



'For appliances complying with Sections 304.2 and 304.3 

^Except for the protection described In (e), all clearances shall be measured from the outer surface of the appliance to the combustible material, 
disregarding any intervening protection applied to the combustible material. 

^Spacers shall be of noncombustible material. 

Note: Insulating millboard is a factory-made product formed of noncombustible materials, normally fibers, and having a thermal conductivity of 1 Btu-inch 
per square foot per degree F [1 .73 W/(m -K)] or less. 



Construction using Combustible Material, 
Wallboard, Plastered or Other Finish 

/ X 



Sheet IVletal or Other Protection 

1 




Appliance or Connector 



A. Dimension shall not be less than the required clearance with no protection set forth in Tables 3-1 and 3-3 
and in the sections applying to various types of appliances. 

B. Dimension shall be not less than the reduced clearance set forth in Table 3-2. , 

C. Dimension shall be not less than the clearance required for dimension A. 

FIGURE 3-1 Extent of Protection Required to Reduce Clearances from Appliance, Chimney, or Vent 
Connectors. 



39 



Table 3-3 



2007 CALIFORNIA MECHANICAL CODE 



TABLE 3-3 

Chimney Connector and Vent Connector Clearances 
from Combustible IVIaterials 



Minimum Clearance/ 


DESCRIPTION OF APPLIANCE 


Inches 


(mm) 


RESIDENTIAL-TYPE APPLIANCES 






Single-Wall Metal Pipe Connectors^ 






Gas appliances without draft hoods 


18 


(457) 


Electric, gas, and oil incinerators 


18 


(457) 


Oil and solid-fuel appliances 


18 


(457) 


Unlisted gas appliances with draft hoods 


9 


(229) 


Boilers and furnaces equipped with listed gas burners 






and with draft hoods 


9= 


(229) 


Oil appliances listed as suitable for use with Type L 






venting systems (but only when connected to chimneys) 


9 


(229) 


Listed gas appliances with draft hoods 


6 


(152) 


Type L Venting System Piping Connectors 






Gas appliances without draft hoods 


g 


(229) 


Electric, gas, and oil Incinerators 


9 


(229) 


Oil and solid-fuel appliances 


9 


(229) 


Unlisted gas appliances with draft hoods 


6 


(152) 


Boilers and furnaces equipped with listed gas burners 






and with draft hoods 


6 


(152) 


Oil appliances listed as suitable for use with Type L 






venting systems" 






Listed gas appliances with draft hoods^ 






Type B Gas Vent Piping Connectors 






Listed gas appliances with draft hoods' 






COMMERCIAL-INDUSTRIAL TYPE APPLIANCES 






Low-Heat Appliances 






Single-Wall Metal Pipe Connectors^ 






Gas, oil, and solid-fuel boilers, furnaces, and water heaters 18 


(457) 


Ranges, restaurant-type 


18 


(457) 


Oil unit heaters 


18 


(457) 


Unlisted gas unit heaters 


18 


(457) 


Listed gas unit heaters with draft hoods 


6 


(152) 


Other low-heat industrial appliances 


18 


(457) 


Medium-Heat Appliances 






Single-Wail Metal Pipe Connectors^ 






All gas, oil, and solid-fuel appliances 


36 


(914) 



Notes: 

'^ These clearances apply except if the listing of an appliance specifies different clearance, in which case the listed clearance takes 
precedence. 

2 The clearances from connectors to combustible materials may be reduced if the combustible material is protected in accordance with 
Table 3-2. 

3 The dimension may be six (6) inches (152 mm), provided the maximum flue temperatures entering the draft hood do not exceed 550°F 
(288''C). 

4 If listed Type L venting system piping is used, the clearance may be in accordance with the venting system listing. 

5 If listed Type B or Type L venting system piping is used, the clearance may be in accordance with the venting system listing. 



40 



GENERAL REQUIREMENTS 



Table 3-4 -Table 3-5 



N 



TABLE 3-4 
Capacities of Listed IVietal Appliance Connectors 

For use with gas pressures 8-inch or more water column (1 .99-kPa) 







' 


Capacities for Various Lengths in Thousands Btu/h 






(basec 


on a pressure drop of 0.2 inch (10.2 mm) water column) 




Flexible 


Natural Gas' of 1,100 Btu/cu. ft. (11.4 W/L) 


Semirigid 


Connector 


















Connector 
O.D.^ 


Nominal 
I.D.= 


1' 


1-1/2' 


2' 


2-1/2' 


3' 


4' 


5' 


6' 






Ranges and 


Inches (mm) 


Inches (mm) 




All Gas Appliances 


Clothes Dryers 


3/8 (9.5) 


1/4 (6.4) 


40 


33 


29 


27 


25 








1/2 (12.7) 


3/8 (9.5) 


93 


76 


66 


62 


58 








5/8 (15.9) 


1/2 (12.7) 


189 


155 


134 


125 


116 


101 


90 


80 


— 


3/4 (19.1) 


404 


330 


287 


266 


244 








— 


1 (25.4) 


803 


661 


573 


534 


500 









Notes: 

^ Gas connectors are certified by the 
valves. Capacities shown are based 
^ Outside diameter. 
^ Internal diameter. 
" For liquefied petroleum gas, use 1 .6 times the natural gas capacities shown. 



testing agency as complete assemblies, Including the fittings and 
on the use of fittings and valves supplied with the connector. 



TABLE 3-5 
Capacities of Listed iVIetai Appliance Connectors 

For use with gas pressures less than 8-inch water column (1 .99-kPa) 







Capacities for Various Lengths In Thousands Btu/h 






(based 


on a pressure drop of 0.2 Inch (10.2 mm) water column) 




Flexible 


Natural Gas^ of 1 ,1 00 Btu/cu. ft. (1 1 .4 W/L) 


Semirigid 


Connector 


















Connector 
O.D.^ 


Nominal 
I.D.= 


1' 


1-1/2' 


2' 


2-1/2' 


3' 


4' 


5' 


6' 






Ranges and 


Inches (mm) 


Inches (mm) 




All Gas Appliances 


Clothes Dryers 


3/8 (9.5) 


1/4 (6.4) 


28 


23 


20 


19 


17 








1/2 (12.7) 


3/8 (9.5) 


66 


54 


47 


44 


41 








5/8 (15.9) 


1/2 (12.7) 


134 


110 ■ 


95 


88 


82 


72 


63 


57 


— 


3/4 (19.1) 


285 


233 


202 


188 


174 








— 


1 (25.4) 


567 


467 


405 


378 


353 









Notes: 

' Gas connectors are certified by the testing agency as complete assemblies, including the fittings and 

valves, Capacities shown are based on the use of fittings and valves supplied with the connector. 
^ Semirigid connector listings are based on the outside diameter. 
^ Flexible connector listings are based on nominal diameter. 
" For liquefied petroleum gas, use 1 .6 times the natural gas capacities shown. 



41 



2007 CALIFORNIA MECHANICAL CODE 



42 



CHAPTER 4 

VENTILATION AIR SUPPLY 



401.0 General. 

This chapter contains requirements for ventilation air 
supply and exhaust, evaporative cooling systems and 
makeup-air requirements for direct-gas-fired heaters, 
industrial air heaters, and miscellaneous heaters. 
[OSHPD 1, 2,3 & 4] See Sections 404.0 through 418.0. 
[SFM] Air filters shall comply with all requirements of 
Part 12, Title 24, Chapter 12-71, SFM Standard 12-71-1. 

402.0 Ventilation Air. [Not permitted for OSHPD 1, 2, 
3&4] 

402.1 General Requirements. [Not permitted for 
OSHPD 1, 2, 3 & 4] All rooms and occupied spaces 
listed in Table 4-1 shall be designed to have 
ventilation (outdoor) air for occupants in accordance 
with this chapter. Ventilation air supply requirements 
for occupancies regulated by the California Energy 
Commission are found in the California Energy Code. 

402.1.1 Construction Documents. The outdoor 
air ventilation rate and air distribution assump- 
tions made in the design of the ventilation system 
shall be clearly identified on the construction 
documents. 

402.2 Natural Ventilation. Use of natural ventilation 
systems designed in accordance with this section 
shall be permitted in lieu of or in conjunction with 
mechanical ventilation systems. [ASHRAE 62.1:5.1] 

Exception: An engineered natural ventilation 
system when approved by the Authority Having 
Jurisdiction need not meet the requirements of 
402.2.1 and 402.2.2. [ASHRAE 62.1:5.1] 

402.2.1 Location and Size of Openings. 
Naturally ventilated spaces shall be permanently 
open to and within twenty-five (25) feet (8 m) of 
operable wall or roof openings to the outdoors, 
the openable area of which is a minimum of 4 
percent of the net occupiable floor area. Where 
the openings are covered with louvers or 
otherwise obstructed, openable area shall be 
based on the free imobstructed area through the 
opening. Where interior spaces without direct 
openings to the outdoors are ventilated through 
adjoining rooms, the opening between rooms 
shall be permanently unobstructed and have a 
free area of not less than 8 percent of the area of 
the interior room nor less than 25 ft^ (2.3 m^). 
[ASHRAE 62.1:5.1.1] 

402.2.2 Control and Accessibility. The means 
to open required operable openings shall be 
readily accessible to building occupants 
whenever the space is occupied. [ASHRAE 
62.1:5.1.2] 



402.3 Mechanical Ventilation. Where natural 
ventilation is not permitted by this section or the 
Building Code, mechanical ventilation systems shaU 
be designed, constructed, and installed to provide a 
method of supply air and exhaust air. The system 
shall operate so that all rooms and spaces are 
continuously provided with the required ventilation 
rate while occupied. 

403.0 Ventilation Rates. The design outdoor air 
intake flow rate for a ventilation system shall be 
determined in accordance with Sections 403.1 
through 403.6. 

403.1 Zone Calculations. Zone parameters shall be 
determined in accordance with Sections 403.1.1 
through 403.1 .3. [ASHRAE 62.1:6.2.2] 

403.1.1 Breathing Zone Outdoor Airflow. The 
design outdoor airflow required in the breathing 
zone of the occupiable space or spaces in a zone, 
i.e., the breathing zone outdoor airflow (Vbz), shall 
be determined in accordance with Equation 4-1. 
[ASHRAE 62.1:6.2.2.1] 



Vhz = RpPz + RaAz 
Where: 



(Equation 4-1) 



Az = zone floor area: the net occupiable floor area of 
the zone ft.2 (m^). 

Pz = zone population: The largest number of people 
expected to occupy the zone during typical usage.. If 
the number of people expected to occupy the zone 
fluctuates, Pz shall be permitted to be estimated based 
on averaging approaches described in Section 403.4. If 
Pz carmot be accurately predicted during design, it 
shall be estimated based on the zone floor area and 
the defatilt occupant density listed in Table 4-1. 

Rp = outdoor airflow rate required per person as 
determined from Table 4-1. 

Ra = outdoor airflow rate required per unit area as 
determined from Table 4-1. [ASHRAE 62.1:6.2.2.1] 

403.1.2 Zone Air Distribution Effectiveness. 

The zone air distribution effectiveness (Ez) shall be 
determined using Table 4-2. [ASHRAE 
62.1:6.2.2.2] 

403.1.3 Zone Outdoor Airflow. The design zone 
outdoor airflow (Voz), i.e., the outdoor airflow that 



43 



403.1-405.0 



2007 CALIFORNIA MECHANICAL CODE 



must be provided to the zone by the supply air 
distribution system, shall be determined in 
accordance with Equation 4-2. [ASHRAE 
62.1:6.2.2.3] 



Yoz = Vbz/Ez 



(Equation 4-2) 



403.2 Single-Zone Systems. When one air handler 
supplies a mixture of outdoor air and recirculated air 
to only one zone, the outdoor air intake flow (Vot) shall 
be determined in accordance with Equation 4-3. 
[ASHRAE 62.1:6.3] 



Vot = Voz 



(Equation 4-3) 



403.3 100% Outdoor Air Systems. When one air 
handler supplies only outdoor air to one or more 
zones, the outdoor air intake flow (Vot) shall be 
determined in accordance with Equation 4-4. 
[ASHRAE 62.1:6.2.4] 



Vot = all zonesVoz 



(Equation 4-4) 



403.4 Muitipie-Zone Recircuiating Systems. When 
one air handler supplies a mixture of outdoor air and 
recirculated return air to more than one zone, the 
outdoor air intake flow (Vot) shall be determined in 
accordance with Sections 403.4.1 through 403.4.4. 
[ASHRAE 62.1:6.2.5] 

403.4.1 Primary Outdoor Air Fraction. When 
Table 4-3 is used to determine system ventilation 
efficiency, the zone primary outdoor air fraction 
(Zp) shall be determined in accordance with 
Equation 4-5. [ASHRAE 62.1:6.2.5.1] 



Zp = Voz/Vpz 



(Equation 4-5) 



Vpz is the primary airflow to the zone from the air 
handler, including outdoor air and recirculated 
return air. [ASHRAE 62.1:6.2.5.1] 

403.4.2 System Ventilation Efficiency. The 

system ventilation efficiency (Ev) shall be 
determined using Table 4-3 or Appendix A of 
ASHRAE 62.1. [ASHRAE 62.1:6.2.5.2] 

403.4.3 Uncorrected Outdoor Air Intalce. The 

design uncorrected outdoor air intake (Vou) shall be 
determined in accordance with Equation 4-6. 
[ASHRAE 62.1:6.2.5.3] 

Vou = D all zones RpPz + all zones RoAz (Equation 4-6), 

The occupant diversity, D, shall be permitted to be used 
to account for variations in occupancy within the 
zones served by the system. [ASHRAE 62.1:6.2.5.3] 

The occupancy diversity is defined as: 
D = Ps/ all zones Pz (Equation 4-7) 



where the system population (Ps) is the total population 
in the area served by the system. Alternative methods 
shall be permitted to be used to account for 
population diversity when calcvilating Vou, provided 
that the resulting value is no less than that detemiined 
by Equation 4-6. [ASHRAE 62.1:6.2.5.3] 

403.4.4 Outdoor Air Intake. The design outdoor 
air intake flow (Vot) shall be determined in 
accordance with Equation 4-8. [ASHRAE 
62.1:6.2.5.4] 



Vot = Vou/Ev 



(Equation 4-8) 



403.5 Design for Varying Operating Conditions. 

403.5.1 Variable Load Conditions. VentLLation 
systems shall be designed to be capable of 
providing the required ventilation rates in the 
breathing zone whenever the zones served by 
the system are occupied, including all full and 
part-load conditions. [ASHRAE 62.1:6.2.6.1] 

403.5.2 Shiort-Term Conditions. If it is known 
that peak occupancy will be of short duration or 
the ventilation rate will be varied or interrupted 
for a short period of time, the design shall be 
permitted to be based on the average conditions 
over a time period T determined by Equation 4-9. 
[ASHRAE 62: Section 6.2.6.2]: 

T = 3v/Vbz (4-9) IP (Equation 4-9) 

where: 

T = averaging time period, (min) 

v = the volume of the zone for which averaging is 

being applied, ft.3 (m^). 

Vbz = the breathing zone outdoor airflow calculated 
using Equation 4-1 and the design value of the zone 
population Pz, cfm (L/s). 

403.6 Dynamic Reset. The system shall be 
permitted to be designed to vary the design outdoor 
air intake flow (Vot), or the space or zone airflow as 
operating conditions change. 

403.7 Exhaust Ventilation. Exhaust airflow shall be 
provided in accordance with the requirements in 
Table 4-4. Exhaust makeup air shall be permitted to 
be any combination of outdoor air, recirculated air, 
and transfer air. 

404.0 Makeup Air. 

Makeup-air requirements for direct gas-fired heaters, 
industrial air heaters, and miscellaneous heaters are 
foiind in Chapters 5 and 9. 



44 



VENTILATION-AIR SUPPLY 



405.0-407.1 



405.0 Evaporative Cooling Systems. 

Evaporative cooling systems shall comply with this 
chapter. 

Evaporative cooliiig systems shall be provided 
with outside air as specified for cooling systems in 
this code. 

Air ducts and fire dampers that arfe a portion of an 
evaporative cooling system shall comply with this code. 

405.1 Location. 

Evaporative cooling systems shall be installed so 
as to minimize the probability of damage from an 
external source. 

405.2 Access, Inspection, and Repair. Evaporative 
coolers shall be accessible for inspection, service, and 
replacement without removing permanent construction; 

405.3 Installation. 

An evaporative cooler supported by the building 
structure shall be installed on a substantial level base 
and shall be secured directly or indirectly to the 
building structure by suitable means to prevent 
displacement of the cooler. 

Modifications made to the supporting 
framework of buildings as a result of the installation 
shall be in accordance with the requirements of the 
Building Code. Openings in exterior walls shall be 
flashed in an approved manner in accordance with 
the requirements of the Building Code. 

An evaporative cooler supported directly by the 
ground shaU be isolated from the ground by a level 
concrete slab extending not less than three (3) inches 
(76 mm) above the adjoining groimd level. 

An evaporative cooler supported on an 
aboveground platform shall be elevated at least six 
(6) inches (152 mm) above adjoining ground level. 

Example: Determine the outdoor air rate required 
for a single zone AC unit serving an interior 2,000 ft.2 
meeting/conference room with a design occupancy 
of 100 people. The system supplies and returns air 
from the ceiling. 

Per Table 4-2, the zone air distribution effectiveness 
is 1.0 since the system supplies cooling only from the 
ceiling. Using the rates from Table 4-1 for a 
meeting/conference room, the minimum system 
outdoor air rate is calculated to be: 

Vot = RpPz + RaAz 
Ez 

= 5 X 100 + 0.06 X 2,000 

1.0 
= 620 cfm 

405.4 Evaporative Cooling System for Health 
Care Facilities [For OSHPD 1, 2, 3 & 4] Direct 
evaporative cooling systems where the air directly contacts 



the wetted surface or spray shall be limited in health 
facilities to nonpatient areas such as laundry rooms, food 
preparation areas and boiler or machinery rooms. Similar 
rooms with high heating-producing equipment will be 
considered when specifically approved by the enforcing 
agency. The evaporative pads, shall be a synthetic type. 
Filters shall be required in accordance with Tables 4-B and 
4-C except utility rooms i.e.: boiler or machinery rooms. 

406.0 Reserved. 

Part I - Ventilation for Health Care Facilities [For 
OSHPD 1,2,3& 4] 

407.0 Ventilation System Details [For OSHPD 1, 2, 
3&4J 

407.1 General. 

407. 1. 1 All supply-air, return air, and exhaust-air 
systems shall be mechanically operated and such 
systems for areas listed in Table 4-A shall be operated 
continuously. Natural ventilation through windows 
or other openings such as louvers will be considered 
as supplemental to the required mechanical 
ventilation systems. 

Exception 1. Natural ventilation shall not be 

used in airborne infection isolation rooms and 

protective environment rooms. 

Exception 2. The number of air changes may be 

reduced to 25 percent of the indicated value in 

Table 4-A, when the room is unoccupied, if 

provisions are made to ensure the following: (1) 

the number of air changes per hour indicated is 

reestablished whenever the space is occupied and 

(2) the pressure relationship with the 

surrounding rooms is maintained when the air 

changes per hour are reduced. In areas requiring 

no continuous directional control as identified in 

accordance with Table 4-A, ventilation systems 

may be shut down when the space is unoccupied 

and ventilation is not otherwise required. 

Ventilation shall not be reduced in rooms 

specifically used for airborne infection control, 

such as waiting rooms, triage rooms, corridors, 

reception areas, areas adjacent to waiting areas, 

airborne infection isolation rooms, negative 

pressure exam room, negative pressure x-ray 

treatment rooms, and protective environment 

rooms. All operating and delivery rooms shall 

maintain a minimum of six air changes per hour 

of total air when not in use. 

407. 1.2 Fans serving exhaust systems shall be 

located at the discharge end of the system. The 

ventilation rates shown in Table 4-A shall be 

considered as minimum acceptable rates and shall 

riot be construed as precluding the use of higher 

ventilation rates if they are required to meet 

design conditions. 



45 



407.2-407.5 



2007 CALIFORNIA MECHANICAL CODE 



407.1.3 Services/Systems and Utilities. See 

Section 313.2. 

407.2 Outdoor Air Intakes and Extiaust 
Outlets. 

407.2.1 Outdoor Air Intakes. Outdoor air intakes 
shall he located at least 25 feet (7.62 m) from exhaust 
outlets of ventilating systems, combustion equipment 
stacks, medical-surgical vacuum systems, cooling 
towers and areas that may collect vehicular exhaust 
or other noxious fumes. The bottom of outdoor air 
intakes shall he located as high as practicable, hut not 
less than 10 feet (3048 mm), above ground level. If 
installed through the roof, they shall he located 18 
inches (457 mm) above roof level or 3 feet (914 mm) 
above aflat roof where heavy snowfall is anticipated. 

Exceptions: 

1. These dimensions may be reduced if it is 
demonstrated by the submission of details and 
calculations that location of intakes with respect 
to exhausts and their orientation, or the use of 
special filters, provides equal performance. 

2. The requirements regarding the bottom of 
outdoor air intakes and installation through the 
roof do not apply to skilled nursing facilities, 
intermediate-care facilities or nonsensitive areas 
in correctional treatment centers. 

407.2.2 Exhaust Outlets. Exhaust outlets shall 
he located a minimum of 10 feet (3048 mm) above 
adjoining grade and 10 feet (3048 mm) from 
doors, occupied areas and operable windows. 
Exception: Airborne infection isolation rooms 
shall comply with Section 414.1. 

407.2.3 Relief Air Discharge. Building relief air 
discharge shall discharge at least 10 feet (3048 
mm) from any outside air intake. 

407.3 Air Balance. 

407.3.1 The ventilation systems shall he designed 
and balanced to provide the general air balance 
relationship to adjacent areas, shown in Table 4-A. 
The ventilation systems shall be balanced in 
accordance with the latest edition of standards 
published by the Associated Air Balanced Council 
(AABC) or the National Environmental Balancing 
Bureau (NEBB). 

407.3.2 Where the variation in static pressure drop 
across filters is a significant portion of the total 
pressure drop, static pressure or pressure differential 
controls or constant volume devices may be required 
to ensure the maintenance of air balance Relationships 
shown in Table 4-A regardless of filter loading. 
Exception: This section does not pertain to skilled 
nursing facilities, intermediate-care facilities and 
nonsensitive areas in correctional treatment centers, 
except for airborne infection isolation rooms and 



protective environment rooms. 

407.4 Air Circulation. 

407.4.1 Air shall be introduced at the cleanest 
areas and removed at the dirtiest areas in order to 
reduce chances of airborne cross infection as 
follows: 

407.4.1.1 Air supplied to operating rooms, 
cesarean operating rooms, cardiac catherization 
labs, cystoscopy rooms, delivery rooms and 
nurseries, shall be delivered at or near the ceiling 
of the area served, and all air removed from the 
area shall he removed near floor level. At least 
two exhaust or recirculation air inlets shall be 
used in all operating and delivery rooms and 
shall be located not less than 3 inches (76 mm) 
nor more than 8 inches (203 mm) above the 
finished floor. 

Exception: Tor airborne infection isolation 
rooms and protective environment rooms, see 
Section 414.0 and 415.0. 

407.4. 1.2 Room supply air outlets and room 
recirculation and exhaust air inlets installed in 
nonsensitive areas shall he located not less than 3 
inches (76 mm) above the floor. 
Exception: For airborne infection isolation 
rooms and protective environment rooms, see 
Section 414.0 and 415.0. 

407.4.1.3 Corridors shall not be used to convey 
supply, return or exhaust air to or from any room 
if the corridor is required to be of fire resistive 
construction per the California Building Code. 
Exception 1: Mechanically exhausted toilet 
rooms of 50 square feet (4.7 m^) or less and small 
rooms of 30 square feet (2.79 m') or less such as 
janitor closets, housekeeping rooms, and 
electrical or telephone closets opening directly 
onto corridor. 

Exception 2: Air transfer caused by pressure 
differentials in rooms required to have a positive 
or negative air balance by Table 4-A. 

407.4. 1.4 No space above a ceiling may he 
utilized as an outside-air, supply-air, exhaust- 
air or return-air plenum. 

Exception: Designs specifically approved by 
the enforcing agency. 

407.4.1.5 Air from a patient room, exam room, 
treatment room shall not be transferred to 
another similar room without first having passed 
through air filters as required b y Table 4-B or 
Table 4-C. 

407.4.1.6 Supply outlets and return and 
exhaust air inlets shall be located to prevent 
short-circuiting. 

407.5 Variable Air Volume. 

407.5.1 Variable Air Volume Systems (VAV). 
Variable air volume systems subjecting the patient to 



46 



VENTILATION-AIR SUPPLY 



407.5 - 408.3 



a fluctuating air movement are not acceptable for 
airborne infection isolation rooms, protective 
environment rooms or those critically sensitive areas 
listed in Table 315. For nonsensitive areas, variable 
air volume systems meeting the following criteria can 
he considered: 

407.5. 1. 1 The VAV system shall comply with 
code requirements for outside air, total air, and 
pressure relationship through the full range of 
operation from minimum to maximum. 

407.5. 1.2 The central return or exhaust fan 
shall be controlled to accomplish the variable air 
volume requirements of the individual rooms 
served by the fan as described in Section 
407.5.1.3. 

407.5.1.3 Variable air volume for return or 
exhaust air shall he accomplished by utilizing an 
automatic modulating damper in the return or 
exhaust air for each zone. The damper will 
modulate from full open to minimum position in 
conjunction with the supply air VAV terminal box. 

408.0 Filters [For OSHPD 1, 2, 3&4] 

408. 1 General, Filter efficiencies shall he certified by the 
manufacturer and shall be based on ASHBAB Standard 
52.1-1992, Gravimetric and Dust-spot Procedures for 
Testing Air-Cleaning Devices Used in General Ventilation 
for Removing Particulate Matter or ASHRAE Standard 
52.2-1999, Method of Testing General Ventilation Air- 
Cleaning Devices for Removal Efficiency by Particle Size 
when specifically set forth in these standards. 

408. 1.1 A filter gauge shall be installed across each 
filter hank serving central air systems. The gauge 
shall he red lined or a filter alarm light installed to 
signal when the recommended maximum static 
pressure drop has been reached. 

408. 1.2 Central air-handling systems are defined as 
any unit requiring duct work on the supply or inlet 
side that serve more than one room. 

408. 1.3 Filter hanks shall be visually inspected for 
torn media and bypass in filter frames by means of a 
flashlight or equivalent, both with fans in operation 
and stopped. Tears in media and bypass in filter 
frames shall be eliminated in accordance with the 
manufacturer's directions and the requirements of the 
enforcing agency prior to commencing operation of 
the system. 

408.1.4 Central air-handling systems shall be 
maintained in a reasonably clean condition during 
construction and shall be cleaned as necessary prior 
to replacement of temporary filter used during 
construction to ensure that clean air will he delivered 
to the occupied spaces. 

408. 1.5 Filter bank No. 1 shall he located upstream 
of the air-conditioning equipment. Filter hank No. 2 

' and filter hank No. 3 shall be located downstream of 
' ■ the supply fan and all cooling and humidification 



equipment with efficiencies as indicated in Table 4-B 
or Table 4-C. 

Exception: Dry steam-type humidifiers for local room 
humidity control may be installed in the supply air 
duct downstream of the final filter bank where designs 
are specifically approved by the enforcing agency. 
408. 1.6 Filter hank No. 2 and filter bank No. 3 media 
shall he rigid or supported (noncollapsing type) and 
shall operate on the principles of impingement, 
straining and diffusion. 
408.2 Filters for Hospitals. 

408.2. 1 All air-ventilation systems shall comply 
with code requirements of this section and shall have 
filter hank efficiencies as listed in Table 4-B. 

408.2.2 Noncentral recirculating air systems 
providing cooling to high heat producing equipment 
located in. nonsensitive areas shall have a filter with 
30 percent average efficiency based on ASHRAE 
Standard 52.1-1992 or a minimum efficiency 
reporting value (MERV) of 8 based on ASHRAE 
Standard 52.2-1999. 

408.2.3 Noncentral air systems serving any areas 
not listed in Table 4-B shall be provided with filter 
arrangement and efficiency specifically approved by 
the enforcing agency. 

408.2.4 Noncentral recirculating air handling 
systems, i.e., through-the-wall units, fan coil units, 
and heat pumps may be utilized for single patient 
rooms of one or more beds. Filtration for these units 
shall have a minimum weight arrestance value of 50 
percent, based on ASHRAE Standard 52.1-1992 or a 
minimum efficiency reporting value (MERV) of 1, 
based on ASHRAE Standard 52.2-1999. The air 
ventilation system providing the minimum air 
changes of outdoor air shall comply with Table 4-B. 
These units may be used as recirculating units only. 
All outdoor air requirements shall be met by a 
separate central air handling systems. 

408.3 Filters for Skilled Nursing Facilities, 
Intermediate Care Facilities and Correctional 
Treatment Centers. 

408.3.1 The air ventilation systems shall comply 
with code requirements of this section for skilled 
nursing facilities, intermediate care facilities and 
correctional treatment centers and shall have filter 
hank efficiencies as listed in Table 4-C. 

408.3.2 Noncentral air systems serving single 
patient rooms of one or more beds shall comply with 
Table 4-C. 

408.3.3 Noncentral recirculating air-handling 
systems, i.e. through the wall units, may he utilized 
for each patient room with one or more beds. 
Filtration for these units shall have a minimum 
weight arrestance value of 50 percent, based on 
ASHRAE Standard 52.1-1992 or a minimum 
efficiency reporting value (MERV) of 1, based on 



47 



408.3-413.2 



2007 CALIFORNIA MECHANICAL CODE 



ASHRAE Standard 52.2-1999. The air ventilation 
system providing the minimum air changes of 
outdoor air shall comply with Table 4r-C. These units 
may he used as recirculating units only. All outdoor 
air requirements shall he met hy a separate central air 
handling system. 

408.3.4 Airhorne infection isolation rooms, 
protective environment rooms and sensitive areas in 
correctional treatment centers shall comply with 
Section 408.2. 
408.4 Filters for Outpatient Faciiities. 

408.4. 1 The air ventilation systems shall comply 
with code requirements of this section for outpatient 
facilities and shall have filter hank efficiencies as 
listed in Table 4-B. 

408.4.2 Noncentral air systems serving individual 
rooms shall comply with Table i-B. 

409.0 DUCTS [FOR OSHPD 1,2,3& 4] 

409.1 Ducts which penetrate construction, intended for 
X-ray or other radiation protection, shall not impair the 
effectiveness of the protection. 

409.2 Duct linings and their use shall meet the 
requirements of Chapter 6, California Mechanical Code. 

409.3 Cold-air ducts shall he insulated wherever 
necessary or to prevent condensation problems. 

409.4 The anchorage and supporting structural elements 
for airducts shall be designed to withstand the lateral 
forces as required hy the California Building Code, Title 
24, Part 2. 

410.0 Laboratories [For OSHPD 1,2,3& 4] 

410.1 The minimum amount of outdoor air in laboratories 
shall he provided in accordance with Table 4-A. A filter 
with 90 percent average efficiency based on ASHRAE 
Standard 52.1-1992 or a minimum efficiency reporting 
value (MERV) of 14, based on ASHRAE Standard 52.2- 
1999 shall be installed in the air-supply system at its 
entrance to the media transfer room. 

410.2 Laboratory hoods for general use shall have a 
minimum average face velocity of 75 feet per minute (380 
m/s). Hoods in which infectious or highly radioactive 
materials are processed shall have a face velocity of 100 
feet per minute (510 m/s). Bacteriological safety cabinets 
used for processing infectious materials shall have an 
average face velocity of 50 to 70 feet per minute (255 m/s 
to 355 m/s) and shall he equipped with a means for 
disinfection. 

410.3 Laboratory hoods shall not be connected to the 
general building exhaust system. Hoods in which 
infectious, incompatible or highly radioactive materials are 
processed each shall have an independent exhaust system 
with the fan installed at the discharge point of the system. 
Duct systems serving laboratory hoods shall be 
constructed of stainless steel of a type which will resist 
corrosion hy materials normally handled. Duct systems 
serving laboratory hoods used for purposes other than 



those needed for routine diagnostic laboratory procedures 
and in which highly radioactive materials or a significant 
volume of highly oxidizing agents are used shall he 
constructed of USS 18-8 stainless steel or the equivalent 
for a minimum distance of 10 feet (3048 mm) from the 
hood. Such ducts shall be equipped with wash down 
facilities and shall he consistent with fire safety 
requirements. Fire dampers and smoke dampers shall not 
he installed in laboratory hood exhaust systems. 
410.4 The exhaust from all laboratory hoods in which 
infectious or radioactive materials are processed shall be 
equipped with filters having a 99 percent efficiency based on 
the DOP (dioctylphthalate) test method or a minimum 
efficiency reporting value (MERV) of 15, based on 
ASHRAE Standard 52.2-1999. Filter frames shall be 
durable and carefully dimensioned, and shall provide an 
airtight fit with the enclosing duct work. All joints between 
filter segments and the enclosing duct work shall he gasketed 
or sealed to provide a positive seal against air leakage. 

411.0 Kitchen and Dining Areas [For OSHPD 1, 2, 
3&4] 

411.1 The air from dining areas may he used to ventilate 
the food preparation areas only after it has passed through 
a filter with at least an 80 percent average efficiency based 
on ASHRAE Standard 52.1-1992 or a minimum 
efficiency reporting value (MERV) of 13, based on 
ASHRAE Standard 52.2-1999. 

Exception: For skilled nursing facilities, 
intermediate care facilities and correctional treatment 
centers, the air from dining area may be used to 
ventilate food preparation areas only after it has 
passed through a filter with a 50 percent average 
efficiency based on ASHRAE Standard 52.1-192 or a 
minimum efficiency reporting value (MEjRV) of 10, 
based on ASHRAE Standard 52.2-1999. 

412.0 Boiier, iVIectianicai and Electrical Rooms 
[For OSHPD 1,2,3& 4] 

412.1 Boiler, heater and electrical equipment rooms shall 
he provided with outdoor air so as to maintain combustion 
rates of equipment and temperatures in the rooms and in 
adjoining areas as rated in this chapter. 

41 2.2 Floor surfaces in occupied spaces above such rooms 
should not exceed a temperature of 85°F (29.4°C), and 
suitable insulation may be required. 

413.0 Odorous Rooms [For OSHPD 1,2, 3 & 4] 

413. 1 Rooms in areas where excessive heat or moisture is 
generated, where ohjectional odors or dust are present, or 
where flammable or toxic gases may accumulate, which 
are used by health facility personnel or patients, shall be 
provided with exhaust ventilation to change the air a 
minimum of ten times per hour. 

413.2 Kitchen, morgues and laundries located inside a 
hospital building or skilled nursing facility in which 
patients are accommodated, or treated, shall be ventilated 



48 



VENTILATION-AIR SUPPLY 



413.2-416.3 



with exhaust systems which will provide a minimum of 
ten air changes per hour and prevent odors from entering 
patient areas. 

414.0 Airborne Infection Isolations Rooms [For 
OSHPD1,2,3&4] 

414.1 Extiaust Systems. A separate, dedicated exhaust 
system shall he provided for airborne infection isolation 
rooms. The dedicated system may serve more than one 
airborne infection isolation room, adjoining toilet rooni 
and anteroom. The exhaust ducts shall be identified by 
appropriate labeling with the words "Caution Airborne 
Infection Isolation Rooms Exhaust" or similar 
terminology. Such labeling shall be in a manner which is 
not readily removable and shall appear on the exhaust 
duct at intervals of not more than 20 feet (6096 mm) and 
at least once near each room and each story traversed by 
the exhaust system. Exhaust fans shall comply with 
Section 407.1.2. The discharge from exhaust fans shall be 
located above the roof and shall he located a minimum of 
25 feet (7620 mm) from areas that may be occupied, doors, 
operable windows, outdoor air intakes, or other openings 
into the building. The exhaust fan discharge shall he 
labeled in a manner which readily identifies the 
precautions which should be observed. To ensure that the 
airborne contaminates do not reenter the building, one of 
the following shall be provided: 

414.1.1 Exhaust discharge from fan. shall extend at 
least 7 feet (2134 mm) above the roof and discharge 
vertically upward. Self-draining stacks or equivalent 
shall be used for rain protection. Rain caps which divert 
the exhaust toward the roof shall he prohibited; or 

414.1.2 Exhaust shall discharge above roof level and 
through an accessible HEP A filter. The HEP A filter 
shall be located upstream of the exhaust fan and have 
a minimum efficiency of 99.97 percent based on the 
DOP method in accordance with Mil-Std. 282 or a 
minimum efficiency reporting value (MERV) of 17, 
based on ASHRAE Standard 52.2 1999. Filter gage 
shall be installed across the filter. For maintenance of 
air balance relationship, see Section 407.3.2. The 25- 
foot (7620 mm) dimension required by Section 414.1 
may be reduced when a 99.97 percent HEP A filter or 
aminimum efficiency reporting value (MERV) of 17, 
liased on ASHRAE Standard 52.2 1999 is used and 
the reduced dimension is specifically approved by the 
enforcing agency. 

414.2 Air Distribution. The supply outlets and exhaust 
inlets shall be located to provide airflow patterns that 
prevent stagnation of the air and eliminate short 
circuiting of the supply to the exhaust, and minimize 
exposure of health care workers to airborne infectious 
particles. Supply-air outlets shall be located at or near the 
ceiling and at the end of the airborne infection isolation 
room which is opposite the head of the hed. Exhaust 



registers shall be located on the wall behind the patient's 
head, or as close to that wall as practical and shall be 
located not less than 3 inches (76 mm) nor more than 24 
inches (610 mm) above the finished floor. 

Exception: For correctional treatment centers, the 
location and design of the supply outlets an exhaust or 
return inlets shall not compromise the safety, security 
and protection of staff, inmates and property. 

415.0 Protective Environment Rooms [For 
OSHPD1,2,3&4] 

415.1 Air Distribution. The supply outlets and exhaust 
and return inlets shall be located to provide airflow patterns 
that prevent stagnation of the air and eliminate short 
circuiting of the supply to the exhaust or return. Supply air 
shall be delivered at or near the ceiling and near the 
patient's bed. All exhaust or return registers shall be located 
near the entrance to the protective environment room and 
not less than 3 inches (76 mm) nor more than 8 inches (203 
mm) above the finished floor. 

Exception: For correctional treatment centers, the 
location and design of the supply outlets and exhaust 
or return inlets shall not compromise the safety, 
security and protection of staff, inmates and property. 

416.0 Alarms - Airborne Infection Isolation 
Rooms and Protective Environment Rooms 
[OSHPD 1,2,3& 4] 

416.1 An alarm system which is based on static pressure 
control, volumetric control, or directional flow 
measurement shall be provided for each isolation room. The 
alarm system shall consist of a display monitor located on 
the corridor wall near the door to the room and a visual and 
audible alarm which annunciates at the room and at a 
nurses' station or other suitable location that will provide 
responsible surveillance. A time delay shall be provided to 
allow for routine openings of doors. The alarm shall 
annunciate when the supply, return, or exhaust fans are 
interrupted and when one of the following conditions is not 
being met during closed door conditions: 

1. When the minimum air quantity difference of 75 
cfln (35.4 Lis) required by Table 4-A is not being 
maintained; or 

2. When a minimum pressure differential of 0.001 

. inch (0.003 kPa) of water and a minimum inward 
(outward for protective environment rooms) air 
velocity of 100 feet per minute (0.508 m/s) is not 
being maintained at the air transfer opening 
required by Table 4-A. 

416.2 Other acceptable alarm systems will be allowed when 
designs are specifically approved by the enforcing agency. 

416.3 [For OSHPD 4] For correctional treatment 
centers, the alarm system shall not create false alarms or 
security hazards. ,. .,;... 



49 



416.4-418.5 



2007 CALIFORNIA MECHANICAL CODE 



416.4 Prior to acceptance of the rooms, the alarm system 
shall be tested and operated to demonstrate to the owner or 
designated representative that the installation and 
performance of the system conforms to design intent. 

417.0 Testing Airborne Infection Isolation Rooms 
and Protective Environment Room [For OSHPD 1, 

2, 3 & 4] Prior to acceptance of the rooms, all mechanical 
systems shall be tested, balanced and^operated to 
demonstrate to the owner or designated representative that 
the installation and performance of the systems conform to 
design intent All testing and balancing shall he performed 
by a qualified independent agency certified by the 
Associated Air Balance Council (AABC) or the National 
Environmental Balancing Bureau (NEBB). Test results 
shall be documented for maintenance files. 

418.0 Design Requirements for Ettiyiene Oxide 
(ETO) Sterilization Areas [For OSHPD 1,2,3& 4] 

418.1 Air Ctianges. The ETO sterilization equipment 
room shall be provided with minimum air changes per hour 
per Table 4-A and be maintained at a negative air balance. 

418.2 Extiaust Requirements. 

418.2.1 All air from the ETO sterilizer equipment 
room shall be exhausted to the outside by a dedicated 
system or other approved method. 

418.2.2 The exhaust fan for the dedicated system shall 
be located at the discharge point of the system and 
identified as ETO Equipment Room Exhaust. 

418.2.3 Discharge Point. The discharge point shall 
be a minimum of 25 feet (7620 mm) away from any 
outside intake, operable window or personnel passage. 

418.3 Ventilation Requirements. 

418.3.1 Aeration units. The aeration units shall be 
ventilated through a nonrecirculating dedicated 
ventilation exhaust system. 

418.3.2 Capture box. When the drain is not located 
in the ETO sterilizer equipment room, ventilation is 
required by a capture box. 

418.3.3 Cylinder change. When not located in the 
ETO sterilizer equipment room, exhaust during cylinder 
change is required by installing a hood that is part of a 
dedicated ventilation exhaust system, positioned no more 
than 1 foot (305 mm) above or behind the point where the 
change of cylinders takes place. 

418.3.4 Sterilizer relief valve. The ventilation of 
sterilizer relief valve is required through a pipe connected 
to the outlet of the relief valve exhausted directly to the 
outdoors at a point high enough to be away from passers- 
by, and not near any windows that open, nor near any 
air-conditioning or ventilation air intakes. 

418.3.5 Ventilation of sterilizer door area. The 
system shall be designed to capture the ETO when the 
door is opened following the completion of the 
sterilization process. A hood or canopy closed on each 



end should be installed over the sterilization door. A 
hood or canopy shall be connected to a dedicated 
exhaust ventilation system. 

418.4 Gas Valves. Installation of gas line hand valves at 
the connection to the supply cylinders are required to 
minimize leakage during cylinder change. 

418.5 Alarm Systems. An Audible an visual alarm 
system shall be installed to alert sterilizer operating personnel 
if the air flow falls below design cubit feet per minute(L/S). 



50 



VENTILATION-AIR SUPPLY 



Table 4-A 



TABLE 4-A - PRESSURE RELATIONSHIP AND VENTILATION REQUIREMENTS FOR 

GENERAL ACUTE CARE HOSPITALS, SKILLED NURSING FACILITIES, 

INTERMEDIATE CARE FACILITIES, CORRECTIONAL 



TREATMENT CENTERS, OUTPATIENTS FACILITIES AND LICENSED CLINICS 



A 


B 


C 


D 


E 


F 




AIRBALANCE 

RELATIONSHIP 

TO 

ADJACENT 

AREAS' 


MINIMUM 

AIR 

CHANGES 

IF 100% 

O.S.A. 


CONDITIONED AIR NOT 
100% O.S.A EXHAUSTE 


ALL AIR 


Area Designation 


Minimum Air 

Changes of 

Outdoor Air 

per hour 


Minimum 

Total Air 

Changes per 

hour 


D 
DIRECTLY 

TO 
OUTDOORS 


Operating room, cardiac cath lab and 
cystoscopy 


P 


12 


5 


20 




Patient holding preparation ' 


E 


6 


2 


6 




Delivery room, cesarean operating room 


P 


12 


5 


20 




Newborn/well baby nursery 


P 


6 


2 


6 




Postanesthesia care unit 


E 


6 


2 


6 


Yes 


Intensive care service spaces. 
Acute respiratory - care sen/Ice spaces. 
Burn service spaces. Coronary - 
care service Spaces, Pediatric 
Intensive - care service spaces' 


P 


6 


2 


6 




Newborn Intensive care 


P 


6 


2 


6 




Emergency department:' 












Waiting area 


N 


12 


2 


12 


Yes' 


Operating room 


P 


12 


5 


20 




Treatment room 


E 


6 


2 


6 




Trauma room^ 


P 


12 


5 


20 




Triage 


N 


12 


2 


12 


Yes 


Patient room 


E 


2 


2 


6 




Patient area corridor 


E 


2 


2 


4 




Labor/dellvery/recovery room, Labor/ 
dellvery/recovery/postpartum room 


E 


2 


2 


6 




Airborne Infection Isolation room 


N" 


12 


2 


12 


Yes 


Alrbone Infection isolation anteroom 


p4 


10 


2 


10 


Yes 


Protective environment room 


ps 


15 


2 


15 




Protective environment anteroom 


N' 


15 


2 


15 




Treatment, and examination rooms 


E 


6 


2 


6 




Bronchoscopy and endoscopy 


N 


12 


2 


12 


. Yes 


Special purpose room (SNF& ICFonly) 


E 


6 


2 


6 


Yes 



51 



Table 4-A cont. 



2007 CALIFORNIA MECHANICAL CODE 



A 


B 


C 


D 


E 


F 




AIRBALANCE 

RELATIONSHIP 

TO 

ADJACENT 

AREAS? 


MINIMUM 

AIR 

CHANGES 

IF 100% 

O.S.A. 


CONDITIONED AIR NOT 
100% O.S.A 


ALL AIR 
EXHAUSTE 


Area Designation 


Minimum Air 

Changes of 

Outdoor Air 

per hour 


Minimum 

Total Air 

Changes per 

hour 


D 
DIRECTLY 

TO 
OUTDOORS 


Radiological/Imaging: 












Angiography Room 


P 


12 


5 


15 




X-ray (diagnostic and treatment) 


E 


6 


2 


6 




CTScan 


E 


6 


2 


6 




MRI room 


E 


6 


2 


6 




Fluoroscopy Room 


N 


6 


2 


6 


Yes 


Dark Room 


N 


12 


2 


12 


Yes 


Negative-pressure x-ray room 


N 


12 


2 


12 


Yes 


Ultra sound room 


E 


6 


2 


6 




Gamma camera 


£ 


6 


2 


6 




Waiting area 


N 


12 


2 


12 


Yes 


Bedpan room 


N 






10 


Yes 


Bathroom 


N 






10 


Yes 


Janitors' closet, Housekeeping room 


N 






10 


Yes 


Sterilizer equipment room 


N 






10 


Yes 


Sub sterile room 


E 


10 


2 


10 


Yes 


Linen and trash chute rooms 


N 






10 


Yes 


Food preparation centers 


E 


10 


2 


10 


Yes 


Dining room 


E 


10 


2 


10 




Dishwashing room 


N 






10 


Yes 


Dietary day storage 


E 






2 




Laundry, general (clean and dirty) 


E 


10 


2 


10 


Yes 


Soiled linen sorting and storage 


N 






10 


Yes 


Clean linen storage 


P 


2 


2 


2 




Anesthesia storage 


E 


8 




8 


Yes 


Central medical and surgical supply: 












Soiled or decontamination room 


N 


4 


2 


4 


Yes 


Clean workroom 


P 


4 


2 


4 




Unsterlle supply 


E 


2 


2 


2 




Pharmacy/medicine room 


P 


2 


2 


4 




Laboratory 












General 


N 


6 


2 


6 




Biochemistry 


P 


6 


2 


6 




Cytology 


N 


6 


2 


6 


Yes 


Glass washing 


N 


10 


2 


10 


Yes 


Histology 


N 


6 


2 


6 


Yes 


Microbiology 


N 


6 


2 


6 


Yes 


Nuclear medicine 


N 


6 


2 


6 


Yes 


Pathology 


N 


6 


2 


6 


Yes 


Serology 


P 


6 


2 


6 




Sterilizing 


N 


10 


2 


10 


Yes 


l\/ledia transfer 


P 


4 


2 


4 





52 



VENTILATION-AIR SUPPLY 



Table 4-A cont. 



A 


B 


C 


D E 


F 




AIRBALANCE 

RELATIONSHIP 

TO 

ADJACENT 

AREASf 


MINIMUM 

AIR 

CHANGES 

IF 100% 

O.S.A. 


CONDITIONED AIR NOT 
100% O.S.A 


ALL AIR 
EXHAUSTE 


Area Designation 


Minimum Air 

Changes of 

Outdoor Air 

per hour 


Minimum 

Total Air 

Changes per 

hour 


D 
DIRECTLY 

TO 
OUTDOORS 


Infectious disease and virus 
Bacteriology 


N 
N 


6 
6 


2 
2 


6 
6 


Yes 
Yes 


Negative-pressure treatment/exam room 


N 


12 


2 


12 


Yes 


Ptiysical therapy and hydrotherapy 


N 


6 


2 


6 




Soiled worl<room (utility room) 


N 


4 


2 


10 


Yes 


Clean worl<room 


P 


4 


2 


6 




Autopsy 


N 


12 


2 


12 


Yes 


Toilet room 


N 






10 


Yes 


Shower room 


N 






10 


Yes 


Waiting area primary care clinic 


N 


. 10 


2 


10 


yes^ 



P = Positive E = Equal N = Negative 

1 The pressure relationship of the entire emergency department shall be negative to other adjacent areas. 

2 Air may be recirculated if a high-efficiency particulate air (HEPA) filter with a minimum efficiency of 99.97 percent or a minimum 
efficiency reporting value (MERV) of 17 is installed in the return air duct which serves the waiting area. 

3 The term "trauma room" as used here is the operating room space In the emergency department or other trauma reception area 
that is used for emergency surgery. The first aid room and/pr "emergency room" used for Initial treatment of accident victims may 
be ventilated as noted for the "treatment rooms. " 

4 The anteroom shall have positive air pressure in relation to the airborne infection isolation room. A door louver, transfer grille, or 
other acceptable means shall be provided to allow for airflow from the anteroom to the airborne infection Isolation room. The 
airborne infection Isolation room shall have negative pressure In relation to the anteroom, and the adjoining toilet room shall have 
negative pressure in relation to the airborne infection isolation room. Negative pressure shall be achieved by balancing the 
exhaust cfm to no less than 75 cfm (35.4 Us) greater than the supply cfm for each airborne infection isolation room the anteroom 
serves. The overall area consisting of the anteroom, airborne Infection Isolation room, and adjoining toilet room shall have an 
equal air balance In relation to the corridor. 

Exception: For correctional treatment centers, the location and design of the air transfer device shall not compromise the 
safety, security and protection of staff. Inmates, and property. 

5 Positive-pressure shall be achieved by balancing the supply cfm to not less than 75 cfm (35.4 Us) greater than the exhaust and 
return cfm for each protective environment room the anteroom sen/es. 

6 The anteroom shall have negative air pressure in relation to the protective environment room. A door louver, transfer grille, or 
other acceptable means shall be provided to allow for airflow from the protective environment room to the anteroom. The 
protective environment room shall have positive-pressure In relation to the anteroom and adjoining toilet room. Positive pressure 
shall be achieved by balancing the supply cfm to not less than 75 cfm (35.4 Us) greater than the exhaust and return cfm. The 
overall area consisting of the anteroom, protective environment room, and adjoining toilet room shall have an equal air balance in 
relation to the corridor. 

Exception: For correctional treatment centers, the location and design of the air transfer device shall not compromise the 
safety, security, and protection of staff, Inmates, and property. 

7 Cystoscopy may have equal air balance relationship to adjacent areas when approved by Authority IHaving Jurisdiction. 

8 For operating rooms, cardiac catheterization labs, angiography rooms, cystoscopy rooms, delivery rooms, cesarean operating 
rooms, newborn intensive care, intensive care units, and nurseries provide approximately 15% excess supply air to the room or a 
sufficient quantity of excess supply air to maintain an appropriate positive air balance based on the room tightness and number of 
doors. For all rooms not listed in this footnote or not listed in Table 315 requiring either a positive or negative air balance, provide 
approximately 10% differential cfm between supply and return/exhaust airflow but not less than 25 cfm differential shall be 
provided regardless of room size. Room function, size, and tightness may be considered when determining the differential airflow 
required. 

9 Intensive care patient rooms, which contain a modular toilet/ sinl< combination unit within the room, shall be provided with a 
minimum of 75 cfm of exhaust directly over the modular toilet/slhl< combination unit. 



53 



Table 4-B- Table 4-C 



2007 CALIFORNIA MECHANICAL CODE 



TABLE 4-B - Filter Efficiencies for Central Ventilation and Alr-Conditioning Systems 
in General Acute Care Hospitals, Acute Psychiatric Hospitals, Outpatient Facilities and Licensed Clinics.^ 



Area Designation 


Minimum Number of Filter Banl<s 


Filter Efficiency % Filter Bank 
(Minimum efficiency reporting 
value MERVY 




No. V 


No. 2' 


No. 3' 


Orthopedic operating room, 
bone marrow transplant 


3 


30% 


90% 


99.97%' 


operating room, organ transplant 
operating room 


(8) 


(14) 


(17) 


Protective environment rooms 


3 


30% 


90% 


99.97%" 




(8) 


(14) 


(17) 


Angiography; cardiac cath iabs; 
operating rooms; delivery rooms 


2 


30% 


90% 




nurseries; patient care, treatment, 
cystoscopy, cesarean operating room, 
diagnostic and related areas; airborne 
infection isolation rooms; areas 
providing direct patient service or clean 
supplies such as sterile and dean 
processes 


(8) 


(14) 




Laboratories 


2 


30% 


80% 






(8) 


(13) 




Administrative, med staff support areas, 
buil< storage, soiled holding areas, 
food preparation areas and laundries 


1 


30% 






(8) 







1 Based on ASHRAE Standard 52. 1-1992 orASHRAE Standard 52.2-1999. 

2 Based on OOP test in accordance with MiL-STD-282 or based on ASHRAE Standard 52.2- 1999. 

3 HEPA fiiters at air outlet or other locations when approved by the Authority Having Jurisdiction. 

4 HEPA filter located in the supply duct which serves the positive-pressure isolation room or rooms may serve more than one supply outlet and more 
than one positive-pressure isolation room. HEPA filter or a filter with minimum efficiency reporting value (I^ERV) of 17 installation shall be designed 
and equipped to permit safe removal, disposal and replacement of filters. 

5 The numbers in parentheses represent li/IERV rating based on ASHRAE Standard 52.2-1999. 

TABLE 4-C - Filter Efficiencies for Central Ventilation and Air-Conditioning Systems 
in Skilled Nursing Facilities and intermediate Care Facilities and Correctional Treatment Centers.^ 





Minimum Number of Filter Banl<s 


Filter Efficiency % Filter Bank 


Area Designation 


(Minimum efficiency reporting 
value MERV)F 




No. V 


No. 2' 


AH areas for inpatient care, treatment 
and/or diagnosis, and those areas 
providing direct service or 
cleaning supplies 


2 


30%, 
(8) 


80% 
(13) 


Administrative, buii< storage, soiled 
holding, laundries and food prep areas 


1 


30%' 
(8) 





1 Based on ASHRAE Standard 52. 1-1992 orASHRAE Standard 52.2-1999. 

2 Filters are not required for evaporative coolers serving laundries and food preparation areas. 

3 The numbers in parentheses represent f\/IERV rating based on ASHRAE 52.2- 1999. 



54 



VENTILATION-AIR SUPPLY 



Table 4-1 



Occupancy 
Category^ 



TABLE 4-1 MINIMUM VENTILATION RATES IN BREATHING ZONE 2,3 

[ASHRAE 62.1 :Table 6-1] 

Note: Ventilation air supply requirements for occupancies regulated by tlie 

California Energy Commission are found in ttie California Energy Code. 

People Outdoor 
Air Rate Rp 
(cfm/person) 



Correctional Facilities 

Cell 5 

Day room 5 

Guard stations 5 

Booking/waiting 7.5 

Educational Facilities 

Day care (through age 4) 10 

Classrooms (ages 5-8) 10 

Classrooms (age 9 plus) 10 

Lecture classroom 7.5 

Lecture hall (fixed seats) 7.5 

Art classroom 10 

Science laboratories ^ 10 

Wood/metal shop 10 

Computer lab 10 

Media center A 10 

Music/theater/dance 10 

Multi-use assembly 7.5 

University/College Laboratories 
Food and Beverage Service 

Restaurant diiung rooms 7.5 

Cafeteria/fast food dining 7.5 

Bars, cocktail lounges 7.5 

General 

Conference /meeting 5 

Corridors 

Storage rooms ^ 

Hotels, Motels, Resorts, Dormitories 

Bedroom/living room 5 

Barracks sleeping areas 5 

Lobbies/pre-function 7.5 

Multipurpose assembly 5 

Office Buildings 

Office space 5 

Reception areas 5 

Telephone /data entry 5 

Main entry lobbies 5 

Miscellaneous spaces 

Bank vaults/safe deposit 5 

Computer (not printing) 5 

Pharmacy (prep, area) 5 

Photo studios 5 
Shipping/receiving ^ 



Area Outdoor 


Default Occupant 


Air Rate R^ 


Density* 


(cha/m 


(people/1,000 ft^) 


0.12 


25 


0.06 


30 


0.06 


15 


0.06 


50 


0.18 


25 


0.12 


25 ■ 


0.12 


35 


0.06 


65 


0.06 


150 


0.18 


20 


0.18 


25 


0.18 


20 


0.12 


25 


0.12 


25 


0.06 


35 


0.06 


. 100 


0.18 


70 ■ 


0.18 


100 


0.18 


100 


0.06 


50 


0.06 


- 


0.12 


- 


0.06 


10 


0.06 


20 


0.06 


30 


0.06 


120 


0.06 


5 


0.06 


30 


0.06 


60 


0.06 


10 


0.06 


5 


0.06 


4 


0.18 


10 


■0.12 


10 


0.12 


- 



55 



Table 4-1 cont. 2007 CALIFORNIA MECHANICAL CODE 



TABLE 4-1 MINIMUM VENTILATION RATES IN BREATHING ZONE 2.3 (continued) 

[ASHRAE62.1:Table6-1] 

Transportation waiting 7.5 0.06 100 

Warehouses^ - 0.06 



Public Assembly Spaces 



Auditorium seating area 


5 


Places of religious worship 


5 


Courtrooms 


5 


Legislative chambers 


5 


Libraries 


5 


Lobbies 


5 


Museums (children's) 


7.5 


Museums / galleries 


7.5 


Retail 




Sales (except as below) 


7.5 


Mall common areas 


7.5 


Barber shop 


7.5 


Beauty and nail salons 


20 


Pet shops (animal areas) 


7.5 


Supermarket 


7.5 


Coin-operated laundries 


7.5 


Sports and Entertainment 




Sports arena (play area) 


- 


Gym, stadium (play area) 


- 


Spectator areas 


7.5 


Swimming (pool & deck) c 


- 


Disco /dance floors 


20 


Health club/aerobics room 


20 


Health club /weight rooms 


20 


Bowling alley (seating) 


10 


Gambling casinos 


7.5 


Game arcades 


7.5 


Stages, studios ^ 


10 



0.06 150 

0.06 120 

0.06 70 

0.06 50 

0.12 10 

0.06 150 

0.12 40 

0.06 40 



0.12 15 

0.06 40 

0.06 25 

0.12 25 

0.18 10 

0.06 8 

0.06 20 



0.30 

0.30 30 

0.06 150 

0.48 

0.06 100 

0.06 40 

0.06 10 

0.12 40 

0.18 120 

0.18 20 

0.06 70 

GENERAL NOTES FOR TABLE 4.1 

2 Smoking: This table applies to no-smoking areas. Rates for smoking-permitted spaces must be determined using other 
methods. 

3 Air Density: Volumetric airflow rates are based on an air density of 1.2 kgda/m^ (0.075 Ibda/ft^), which corresponds to 
dry air at a barometric pressure of 101.3 kPa (1 atm) and an air temperature of 21 °C (70 °F). Rates shall be permitted to be 
adjusted for actual density but such adjustment is not required for compliance with this chapter. 

4 Default Occupant Density: The default occupant density shall be used when actual occupant density is not known. 
6 Unlisted Occupancies: If the occupancy category for a proposed space or zone is not listed, the requirements for the 

listed occupancy category that is most similar in terms of occupant density, activities, and building construction shall be 
used. 

ITEM-SPECIFIC NOTES FOR TABLE 4.1 

A For high school and college libraries, use values shown for Public Spaces - Library. 

B Rate may not be sufficient when stored materials include those having potentially harmful emissions. 

C Rate does not allow for humidity control. Additional ventilation or dehumidification may be required to remove 

moistiire. 
D Rate does not include special exhaust for stage effects, e.g., dry ice vapors, smoke. 
E No class of air has been established for this occupancy category. 



56 



VENTILATION-AIR SUPPLY Table 4-2 & Table 4-3 



TABLE 4-2 
Zone Air Distribution Effectiveness 

[ASHRAE 62.1 Table 6-2] 

Air Distribution Configuration Ez 

Ceiling supply of cool air 1.0 

Ceiling supply of warm air and floor return 1.0 

Ceiling supply of warm air at least 15°F (8°C) above space temperature 0.8 

and ceiling return. 

Ceiling supply of warm air less than 15°F (8°C) above space , . .1.0 

temperature and ceiling return provided that the 150 fpm (0.8 m/s) 
supply air jet reaches to within 4.5 ft. (1.4 m) of floor level. 

Floor supply of cool air and ceiling return provided that the 150 fpm 1.0 

(0.8 m/s) supply jet reaches at least 4.5 ft. (1.4 m) above the floor. 

Floor supply of cool air and ceiling return, provided low velocity 1.2 

displacement ventilation achieves unidirectional flow and thermal 
stratification. 

Floor supply of warm air and floor return 1.0 

Floor supply of warm air and ceiling return 0.7 

Makeup supply drawn in on the opposite side of the room from the 0.8 

exhaust or return. 

Makeup supply drawn in near to the exhaust or return location 0.5 

Notes for Table 4-2 

1. "Cool air" is air cooler than space temperature. 

2. "Warm air" is air warmer than space temperature. 

3. "Ceiling" includes any point above the breathirig zone. 

4. "Floor" includes any point below the breathing zone. 

5. As an alternative to using the above values, determine Ez in accordance with ASHRAE Standard 129 for all air 
distribution.configurations except unidirectional flow. 

TABLE 4-3 
System Ventilation Efficiency 

[ASHRAE 62.1 Table 6-3] 

Max {Zp). Ev 

- ■ ■ < 0.15 1.0 

< 0.25 0.9 

< 0.35 0.8 
<0.45 0.7 
<0.55 0.6 

>0.55- Use ASHRAE 62.1, Apperidbc A 

Notes for Table 4-3. 

1. "Max Zp" refers to the largest value of Zp, calculated using Equation 4-5, among all the zones served by the system. 

2. Interpolating between table values is permitted. 



57 



Table 4-4 



2007 CALIFORNIA MECHANICAL CODE 



TABLE 4-4 Minimum Exhaust Rates 

[ASHRAE 62.1 :Table 6-4] 



Occupancy Category 


Exhaust Rate 


Exhaust Rate 


Exhaust Rate 


Exhaust Rate 




cfm/unit 


cfm/ft2 


L/s-unit 


L/s-m2 


Art classrooms 


- 


0.70 


- 


3.5 


Auto repair rooms i 


- 


1.50 


- 


7.5 


Barber shop 


- 


0.50 


- 


2.5 


Beauty and nail salons 


- 


0.60 


- 


3.0 


Cell with toilet 


- 


1.00 


- 


5.0 


Darkrooms 


- 


1.00 


- 


5.0 


Arena 2 


- 


0.50 


- 


2.5 


Kitchen - commercial 


- 


0.70 


- 


3.5 


Kitchenettes 


- 


0.30 


- 


1.5 


Locker rooms 


- 


0.50 


- 


2.5 


Locker/ dressing rooms 


- 


0.25 


- 


1.25 


Parking garages 3 


- 


0.75 


- 


3.7 


Janitor, trash, recycle 


- 


1.00 


- 


5.0 


Pet shops (animal areas) 


- 


0.90 


- 


4.5 


Copy, printing rooms 


- 


0.50 


- 


2.5 


Science lab classrooms 


- 


1.00 


- 


5.0 


Toilets - public * 


50/70 


- 


25/35 


- 


Toilet - private ^ 


25/50 


- 


12.5/25 


- 


Woodwork shop / classroom 


- 


0.50 


- 


2.5 



Notes For Table 4-4 

1 Stands where engines are run shall have exhaust systems that directly connect to the engine exhaust and prevent escape 
of fumes. 

2 The rates do not include exhaust from vehicles or equipment with internal combustion engines. 

3 Exhaust not required if two or more sides comprise walls that are at least 50% open to the outside. 

4 Rate is per water closet or urinal. Provide the higher rate where periods of heavy use are expected to occur, e.g., toilets in 
theatres, schools, and sports facilities. 

5 Rate is for a toilet room intended to be occupied by one person at a time. For continuous system operation during normal 
hours of use, the lower rate may be used. Otherwise use the higher rate. 



58 



CHAPTER 5 



EXHAUST SYSTEMS 
Note: Portions of this chapter have been reproduced in their entirety from NFPA 96-1999. 



501.0 Scope. 

This chapter includes requirements for environmental 
air ducts, product-conveying systems, and 
commercial hoods and kitchen ventilation. 

Part i - Environmental Air Ducts and Product- 
Conveying Systems 

502.0 Definitions. 

For the purposes of this chapter, the following 
definitions apply: 

ACCESS PANEL. A closure device used to cover an 
opening into a duct, an enclosure, equipment, or an 
appurtenance. 

AIR INTAKES. An opening in a building's envelope 
whose purpose is to allow outside air to be drawn 
into the structure to replace inside air that is 
removed by exhaust systems or to improve the 
quality of the inside air by providing a source of air 
having a lower concentration of odors, suspended 
particles, or heating content. 

AIR POLLUTION CONTROL DEVICES. Equipment 
and devices used for the purpose of cleaning air 
passing through them or by them in such a maimer as 
to reduce or remove the impurities contained therein. 

APPURTENANCE. An accessory or a subordinate 
part that enables the primary device to perform or 
improve its intended function. 

AUTOMATIC. That which provides a function 
without the necessity of human intervention. [NFPA 
96: 3.3.6] 

BAFFLE PLATE. An object placed in or near an 
appliance to change the direction or retard the flow 
of air, air-fuel mixtures, or flue gases. 

CERTIFIED. A formally stated recognition and 
approval of an acceptable level of competency, 
acceptable to the Authority Having Jurisdiction. 
[NFPA 96 3.3.9] 

CLASSIFIED. See Listed. 

CLEARLY IDENTIFIED. Capable of being 
recognized by a person of normal vision without 
causing uncertainty and indecisiveness about the 
location or operating process of the identified item. 

CLOSED COMBUSTIBLE CONSTRUCTION. 

Combustible building construction, including walls. 



structural framing, roofs, roof ceilings, floors, and 
floor-ceiling assemblies continuously enclosing a 
grease duct on four sides where one or more sides 
require protection per Section 507.2. 

COMBUSTIBLE MATERIAL. Material subject to an 
increase in combustibility or flame-spread rating 
beyond the limits established in the definition of 
Limited-Combustible Material. 

COMMERCIAL FOOD HEAT-PROCESSING 
EQUIPMENT. Equipment used in a food 
establishment for heat-processing food or utensils 
and that produces grease vapors, steam, fumes, 
smoke, or odors that are required to be removed 
through a local exhaust ventilation system. 

COMPENSATING HOOD. A hood that has an 
outside-air supply with air delivered below or 
within the hood. When makeup air is diffused 
directly into the exhaust within the hood cavity, it 
becomes a short-circuit hood. 

CONCEALED SPACES. That portion(s) of a building 
behind walls, over suspended ceilings, in pipe chases, 
attics, and elsewhere whose size might normally 
range from 1-3/4 inch (44.45 mm) stud spaces to 
eight (8) foot (2.44 m) interstitial truss spaces and that 
might contain combustible materials such as building 
structural members, thermal and /or electrical 
insulation, and ducting. Such spaces have sometimes 
been used as HVAC plenum chambers. 

CONTINUOUS ENCLOSURE. A recognized architec- 
tural or mechanical component of a building having a 
fire resistance rating as required for the structure and 
whose purpose is to enclose the vapor removal duct 
for its full length to its termination point outside the 
structure without any portion of the enclosure having 
a fire resistance rating less than the required value. 

CONTINUOUS WELD. A metal-joining method that 
produces a product without visible interruption or 
variation in quality. For the purpose of the definition, 
it specifically includes the exhaust compartment of 
hoods and welded joints of exhaust ducts, yet 
specifically does not include filter support frames or 
appendages inside hoods. 

COOKING APPLIANCE FLUE OUTLET. The 

opening or openings in a cooking device where 
vapors, combustion gases, or both leave the cooking 
device. There might or might not be ductwork 
attached to this opening. 



59 



502.0 



2007 CALIFORNIA MECHANICAL CODE 



DAMPER. A valve or plate within a duct or its 
terminal components for controlling draft or the flow 
of gases, including air. 

DETECTION DEVICES. Electrical, pneumatic, 
thermal, mechanical, or optical sensing instruments, 
or subcomponents of such instruments, whose 
purpose is to cause an automatic action upon the 
occurrence of some preselected event. In the context 
of this document, the event in question could be 
excessive temperature or flame, and the action could 
be the operation of a fire-extinguishing system. 

DIPS. Depression or cuplike places in horizontal 
duct runs in which liquids could accumulate. 

DISCHARGE. The final portion of a duct or pipe 
where the product being conveyed is emptied or 
released from confinement; the termination point of 
the pipe or duct. 

EASILY ACCESSIBLE. See Accessible, Readily in 

Section 203.0, Chapter 2. 

ENVIRONMENTAL AIR DUCT. Ducting used for 
conveying air at temperatures not exceeding 250°F 
(121 °C) to or from occupied areas of any occupancy 
through other than heating or air-conditioning 
systems, such as ventilation for human usage, 
domestic kitchen range exhaust, bathroom exhaust 
ducts, and domestic-type clothes dryer exhaust ducts. 

FACTORY-BUILT GREASE ENCLOSURES. A Usted 
factory-built grease duct enclosure system evaluated 
for reduced clearances to combustibles, and as an 
alternative to a duct with its fire-rated enclosure. 

FIELD-APPLIED GREASE DUCT ENCLOSURES. 

A listed system evaluated for reduced clearances to 
com.bustibles, and as an alternative to a duct with its 
fire-rated enclosure. - 

FLAMMABLE VAPOR OR FUMES. The concen- 
tration of flammable constituents in air that exceeds 
twenty-five percent (25%) of its lower flammability 
limit (LFL). 

FIRE BARRIER WALL. A wall assembly complying 
with the requirements of NFPA 221, Standard for 
Fire Walls and Fire Barrier Walls, having a fire 
resistance rating of four (4) hours. 

FIRE PARTITION. An interior wall or partition of a 
building that separates two areas and serves to restrict 
the spread of fibre but does not qualify as a fire wall. 

FIRE RESISTANCE RATING. A relative value in 
minutes or hours assigned to materials or assemblies 
that have withstood a fire exposure as established in 
accordance with NFPA 251, Standard Methods of 
Tests of Fire Endurance of Building Construction 
and Materials. 



FUME INCINERATORS. Devices utilizing intense 
heat or fire to break down and /or oxidize vapors 
and odors contained in gases or air being exhausted 
into the atmosphere. 

FUSIBLE LINK. A form of fixed-temperature heat- 
detectkig device sometimes employed to restrain the 
operation of an electrical or mechanical control imtil 
its designed temperature is reached. Such devices are 
to be replaced following each operation. 

GREASE. Rendered animal fat, vegetable shortening, 
and other such oily matter used for the purposes of 
and resulting from cooking and/or preparing foods. 
Grease might be liberated and entrained with exhaust 
ak or might be visible as a Uqmd or solid. 

GREASE DUCTS. A containment system for the 
transportation of air and grease vapors that is designed 
and installed to reduce the possibility of the 
accumulation of combustible condensation and the 
occurrence of damage if a fire occurs within the system. 

GREASE FILTER. A removable component of the 
grease removal system designed to capture grease 
and direct it to a safe collection point before it enters 
a duct system. Filters are expected to minimize the 
projection of flames downstream when attacked by 
flame on the upstream side and are expected to 
inaintain their strength, shape, and integrity when 
exposed to the anticipated rough handling, cleaning, 
and service found in the field. 

GREASE FILTER, MESH-TYPE. A general-purpose 
air filter designed to collect and retain lint and grease 
from the air passing through it. This type of filter is 
not tested, listed, or acceptable for commercial 
cooking operations due to the increased fire hazard. 

GREASE REMOVAL DEVICES. A system of 
components designed for and intended to process 
vapors, gases, and /or air as it is drawn through such 
devices by collecting the airborne grease particles 
and concentrating them for further action at some 
future time, leaving the exiting air with a lower 
amotmt of combustible matter. 

GREASETIGHT. Constructed and performing in 
such a manner as not to permit the passage of any 
grease under normal cooking conditions. 

HIGH BROILER. See Upright Broiler. 

HIGH LIMIT CONTROL. An operating device 
installed in and serving as an integral component of 
a deep-fat fryer. Its purpose is the secondary 
limitation of temperature allowed by the cooking 
operation and, if that temperature is exceeded, the 
automatic interruption of the thermal energy input. 

HOOD. An air-intake device connected to a mechanical 
exhaust system for collecting and removing grease. 



60 



EXHAUST SYSTEMS 



502.0 



vapors, fumes, smoke, steam, heat, or odors from 
comm.ercial food heat-processing equipment. 

Fixed Baffle. A listed unitary exhaust hood 
design where the grease removal device is a 
nonremovable assembly that contains an 
integral fire-activated water-wash fire- 
extinguishing system listed for this purpose. 

Type I is a kitchen hood for collecting and 
removing grease and smoke. 

Type II is a general kitchen hood for collecting 
and removing steam, vapor, heat, or odors. 

INTERCONNECTED. Mutually assembled to 
another component in such a manner that the 
operation of one directly affects the other or that the 
contents of one specific duct system are allowed to 
encounter or contact the products being moved by 
another duct systerh. 

LABELED. Equipment or materials to which has 
been attached a label, symbol, or other identifying 
mark of an organization that is acceptable to the 
Authority Having Jurisdiction and concerned with 
product evaluation, that maintains periodic 
inspection of production of labeled equipment or 
materials, and by whose labeling the manufacturer 
indicates compliance with appropriate standards or 
performance in a specified manner. 

LIMITED-COMBUSTIBLE MATERIAL. A building 
construction material that does not comply with the 
definition of noncombustible material, that, in the 
form in which it is used, has a potential heat value 
not exceeding 3,500 Btu/lb. (8141 kj/kg)(see NFPA 
259, Standard Test Method for Potential Heat of 
Building Materials), and that compHes with either of 
the following (A) or (B). Materials subject to an 
increase in combustibility or flame-spread rating 
beyond the limits herein established through the 
effects of age, moisture, or other atmospheric 
conditions shall be considered combustible. 

(A) Materials having a structural base of 
noncombustible material, with a surfacing 
not exceeding a thickness of 1/8 inch (3.2 
mm), and with a flame-spread rating not 
greater than fifty (50). 

(B) Materials in the form and thickness used, 
other than as described in (A), having neither 
a flame-spread rating greater than twenty- 
five (25) nor evidence of continued progressive 
combustion and of such composition that 
surfaces that would be exposed by cutting 
through the material on any plane would 
have neither a flame-spread rating greater 
than twenty-five (25) nor evidence of 
continued progressive combustion. 



LIQUIDTIGHT. Constructed and performing in such a 
manner as not to permit the passage of any liquid at any 
temperature. 

LISTED. Equipment, materials, or services included 
in a list published by an organization that. is 
acceptable to the Authority Having Jurisdiction and 
concerned with evaluation of products or services, 
that maintains periodic inspection of production of 
listed equipment or materials or periodic evaluation 
of services, and whose listing states that the 
equipment, material, or service meets identified 
standards or has been tested and found suitable for a 
specified purpose. 

NONCOMBUSTIBLE MATERIAL. A material that, 
in the form in which it is used and under the 
conditions anticipated, will not ignite, burn, support 
combustion, or release flammable vapors when 
subjected to fire or heat. Materials that are reported 
as passing ASTM E 136, Standard Test Method for 
Behavior of Materials in a Vertical Tube Furnace at 
750°C, shall be considered noncombustible materials. 

OPEN COMBUSTIBLE CONSTRUCTION. Combustible 
building constructions including wall, structural 
framing, roof, roof ceiling, floor, and floor ceiling' 
assemblies adjacent to a grease duct on three or 
fewer sides where one or more sides require 
protection per Section 507.2. 

PITCHED. To be fixed or set at a desired angle or 
inclination. 

PRODUCT-CONVEYING DUCT. Ducting used for 
conveying solid particulates, such as refuse, dust, 
fumes, and smoke; liquid particulate matter, such as 
spray residue, mists, and fogs; vapors, such as 
vapors from flammable or corrosive liquids; noxious 
and toxic gases; and air at temperatures exceeding 
250°F (121°C). 

QUALIFIED. A competent and capable person or 
company that has met the requirements and training 
for a given field acceptable to the Authority Having 
Jurisdiction. [NFPA 96: 3.3.37] 

RECIRCULATING SYSTEMS. Systems for contirol of 
smoke or grease-laden vapors from commercial 
cooking equipment that do not exhaust to the outside. 

REMOVABLE. Capable of being transferred to 
another location with a limited application of effort 
and tools. 

REPLACEMENT AIR. See Air, Makeup in Section 
203.0, Chapter 2. 

SALAMANDER BROILER. See Upright Broiler. 
SHALL. Indicates a mandatory requirement. 

SINGLE HAZARD AREA. As considered in the 
applicable extinguishing system standard (see 



61 



502.0 - 503.2 



2007 CALIFORNIA MECHANICAL CODE 



Section 513.2) or as determined by the Authority 
Having Jurisdiction. 

SOLID COOKING FUEL. Any solid, organic, 
consumable fuel such as briquettes, mesquite, 
hardwood, or charcoal. 

SOLID-FUEL COOKING EQUIPMENT. Cooking 
equipment that is fired with solid cooking fuel. This 
equipment includes ovens, tandoori charcoal pots, 
grills, broilers, rotisseries, barbecue pits, or any other 
type of cooking equipment that derives aU or part of 
its heat source from the burning of solid cooking fuel. 

SOLVENT. A substance (usually liquid) capable of 
dissolving or dispersing another substance; a 
chemical compound designed and used to convert 
solidified grease into a liquid or semiliquid state in 
order to facilitate a cleaning operation. 

SPARK ARRESTER. A device or method that 
minimizes the passage of airborne sparks and 
embers into a plenum, duct, and flue. 

STANDARD. A document, the main text of which 
contains only mandatory provisions using the word 
"shall" to indicate requirements and that is in a form 
generally suitable for mandatory reference by another 
standard or code or for adoption into law. 
Nonmandatory provisions shall be located in an 
appendix, footnote, or fine-print note and are not to be 
considered a part of the requirements of a standard. 

TERMINATION. The final or intended end portion of 
a duct system that is designed and functioiiis to fulfill 
the obligations of the system in a satisfactory manner. 
THERMAL RECOVERY UNIT. A device or series of 
devices whose purpose is to reclaim or\ly the heat 
content of air, vapors, gases, or fluids that are being 
expelled through the exhaust system and to transfer 
the thermal energy so reclaimed to a location 
whereby a useful purpose can be served. 

TRAINED. A person who has become proficient in 
performing a skill reliably and safely through 
instruction and practice /field experience acceptable 
to the Authority Having Jurisdiction. [NFPA 96 
3.3.47] 

TRAP. A cuplike or U-shaped configuration located 
on the inside of a duct system component where 
liqmds can accumulate. 

UPRIGHT BROILER. An appliance used in the 
preparation of food whereby foods are exposed to 
intense radiant heat, and perhaps to convective heat, 
with the food and the radiant source not limited to a 
horizontal mode. 

502.1 Product-Conveying Ducts - Classification. 

Product-conveying ducts shall be classified 
according to their use, as follows: 



Class 1. Ducts convejdng nonabrasives, such as 
smoke, spray, mists, fogs, noncorrosive fumes 
and gases, light fine dusts, or powders. 

Class 2. Ducts conveying moderately abrasive 
particulate in light concentrations, such as 
sawdust and grain dust, and buffing and 
polishing dust. 

Class 3. Ducts conveying Class 2 materials in 
high concentrations and highly abrasive 
materials in low concentrations, such as 
manganese, steel chips, and coke. 

Class 4. Ducts conveying highly abrasive 
material in high concentrations. 

Class 5. Ducts conveying corrosives, such as 
acid vapors. 

503.0 Motors, Fans, and Filters. 

503.1 General. Motors and fans shall be sized to 
provide the required air movement. Motors in areas 
that contain flammable vapors or dusts shall be of a 
type approved for such environments. A manually 
operated remote control installed at an approved 
location shall be provided to shut off fans or blowers 
in flammable vapor or dust systems. Electrical 
equipment used in operations that generate explosive 
or flammable vapors, fumes, or dusts shall be 
interlocked with the ventilation system so that the 
eqtiipment caimot be operated unless the ventilation 
fans are in operation. Motors for fans used to convey 
flammable vapors or dusts shall be located outside 
the duct or shall be protected with approved shields 
and dustproofing. Motors and ians shall be accessible 
for servicing and maintenance. 

503.2 Fans. Parts of fans in contact with explosive or 
flammable vapors, fumes, or dusts shall be of 
nonferrous or nonsparking materials or their casing 
shall be lined or consttucted of such material. When 
the size and hardness of materials passing through a 
fan could produce a spark, both the fan and the 
casing shall be of nonsparking materials. When fans 
are required to be spark-resistant, their bearings 
shall not be within the airstream, and all parts of the 
fan shall be grounded. Fans in systems handling 
materials that are likely to dog the blades, and fans 
in buffing or woodworking exhaust systems, shall be 
of the radial-blade or tube-axial type. 

Equipment used to exhaust explosive or 
flammable vapors, fumes, or dusts shall bear an 
identification plate stating the ventilation rate for 
which the system was designed. 

Fans located in systems conveying corrosives 
shall be of materials that are resistant to tiie corrosive 
or shall be coated with corrosion-resistant materials. 



62 



EXHAUST SYSTEMS 



503.3 - 504.5 



503.3 Air filters shall be listed units. Liquid adhesive 
coatings used on filters shall have a flash point of 
350°F (177°C) or higher, as determined by the Fire 
Code standards. 



504.0 Environmental Air Ducts. 

504.1 iVIaiteup and Exhaust-Air Ducts. Environ- 
mental air ducts not regulated by other provisions of 
this code shall comply with this section. Ducts shall 
be substantially airtight and shall comply with the 
provisions of Chapter 6. Exhaust ducts shall not 
extend into or through ducts or plenums. Exhaust 
ducts shall terminate outside the building and shall 
be equipped with back-draft dampers. [For OSHPD 
1, 2 & 4] Exception: Back-draft dampers are not required 
when the exhaust fan must operate continuously. 
Environmental air ducts that have an alternate 
function as a part of an approved smoke-control 
system do not require design as Class 1 
product-conveying ducts. 

504.2 Domestic Range Vents. Ducts used for domestic 
kitchen range ventilation shall be of metal and shall 
have smooth interior surfaces. Ducts for domestic range 
hoods shall only serve cooking appliances. 

Exception: Ducts for domestic kitchen 
downdraft griU-range ventilation installed under 
a concrete slab floor may be of approved 
Schedule 40 PVC provided: 

(1) The under-floor trench in which the duct is 
installed shall be completely backfilled with 
sand or gravel. 

(2) Not more than one (1) irich (25.4 mnx) of six 
(6) inch diameter (152 mm) PVC coupling 
may protrude above the concrete floor siorface. 

(3) PVC pipe joints shall be solvent cemented to 
provided an air and grease-tight duct. 

(4) The duct shall terminate above grade 
outside the building and shall be equipped 
with a back-draft damper. 

504.3 Clothes Dryers. 

504.3.1 IVIoisture Exhaust Ducts. Moisture 
exhaust ducts shall terminate on the outside of 
the building and shall be equipped with a back- 
draft damper. Screens shall not be installed at the 
duct termination. Ducts for exhausting clothes 
dryers shall not be coimected or installed with 
sheet metal screws or other fasteners that will 
obstruct the flow. Clothes dryer moisture exhaust 
ducts shall not be connected to a gas vent 
connector, gas vent, or chimney, and shall only 
serve clothes dryers. Clothes dryer moisture 



exhaust ducts shall not extend into or through 
ducts or plenums. 

504.3.2 Domestic Clothes Dryers. When a 
compartment or space for a domestic clothes 
dryer is provided, a minimum four (4) inch 
diameter (102 mm) moisture exhaust duct of 
approved material shall be installed in 
accordance with this section and Section 504.0. 

When a closet is designed for the installation 
of a clothes dryer, a minimum opening of 100 
square inches (64,516 nrni^) for makeup air shall be 
provided in the door or by other approved means. 

504.3.2.1 Domestic Dryer Vents. Domestic 
clothes dryer moisture exhaust ducts shall 
be of metal and shall have smooth interior 
surfaces. 

Exception: Listed clothes dryer transition 
ducts not more than six (6) feet (1,829 mm) 
in length may be used in connection 
with domestic dryer exhausts. 

Flexible clothes dryer transition 
ducts shall not be concealed within 
construction. 

504.3.2.2 Length Limitation. Unless 
otherwise permitted or required by the dryer 
manufacturer's installation instructions and 
approved by the Authority Having 
Jurisdiction, domestic dryer moisture 
exhaust ducts shall not exceed a total 
combined horizontal and vertical length of 
fourteen (14) feet (4,263 mm), including two 
(2) 90 degree (1.57 rad) elbows. Two (2) feet 
(610 mm) shall be deducted for each 90 
degree (1.57 rad) elbow in excess of two. 

504.3.3 Commercial Clothes Dryers. Coimner- 
cial dryer exhaust ducts shall be installed in 
accordance with their listings. The installation of 
commercial clothes dryer exhaust ducts shall 
comply with the appliance manufacturer's 
installation instructions. 

504.4 Heat (Energy) Recovery Ventilators. 

504.4.1 Heat (energy) recovery ventilators shall 
be installed in accordance with their listings and 
comply with the appliance manufacturer's 
installation instructions. Heat (energy) recovery 
ventilator ducts shall comply with the 
provisions of Chapter 6. 

504.5 Termination of Environmental Air Ducts. 

Environmental air duct exhaust: three (3) feet (914 
mm) from property line; three (3) feet (914 mm) from 
openings into the building. 



63 



504.6 -Table 5-1 



2007 CALIFORNIA MECHANICAL CODE 



504.6 Gypsum Wallboard Ducts. Bathroom and 
laundry room exhaust ducts may be of gypsum 
wallboard subject to the limitations of Section 602.1. 

505.0 Design of Product-Conveying Ventilation 
Systems. 

505.1 General. A mechanical ventilation or exhaust 
system shall be installed to control, capture, and 
remove emissions generated from product use or 
handling when required by the Building Code or 
Fire Code and when such emissions result in a 
hazard to life or property. The design of the system 
shall be such that the emissions are confined to the 
area in which they are generated by air currents, 
hoods, or enclosures and shall be exhausted by a 
duct system to a safe location or treated by removing 
contaminants. Ducts conveying explosives or 
flammable vapors, fumes, or dusts shall extend 
directly to the exterior of the building without 
entering other spaces and shall not extend into or 
through ducts and plenums. 

ExGeption: Ducts conveying vapor or fumes 
having flammable constituents less than 25 
percent of their lower flammability limit (LFL) 
may pass through other spaces. 

505.1.1 Incompatible materials shall not be 
conveyed in the same system. 

505.1.2 In systems conveying flammable 
vapors, gases, or mists, the concentration shall 
not exceed 25 percent of the lower flammability 
limit (LFL). ; 

Exceptioii: Higher concentrations shall be 
permitted if the exhaust system is designed 
and protected in accordance with the 



Standard on Explosion Prevention Systems 
in Chapter 17, using one or more of the 
following techniques: 

(a) Combustible concentration reduction 

(b) Oxidant concentration reduction 

(c) Deflagration suppression 

(d) Deflagration pressure containment 

Separate and distinct systems shall be provided for 
incompatible materials. 

Contaminated air shall not be recirculated to 
occupied areas unless contaminants have been 
removed. Air contaminated with explosive or 
flammable vapors, fumes, or dusts; flammable or toxic 
gases; or radioactive material shall not be recirculated. 

505.2 Minimum Velocities and Circulation. The 

velocity and circulation of air in work areas shall be 
such that contaminants are captured by an airstream 
at the area where the emissions are generated and 
conveyed into a product-conveying duct system. 
Mbcttires within work areas where contaminants are 
generated shall be diluted below 25 percent of their 
lower explosive limit or lower flammability limit 
with air that does not contain other contaminants. 
The velocity of air within the duct shall be not less 
than set for th in Table 5-1 . 

Systems for removal of vapors, gases, and smoke 
shall be designed by the constant velocity or equal 
friction methods. Systems conve5dng particulate matter 
shall be designed employing the constant velocity 
method. Systems conveying explosive or radioactive 
materials shall be prebalanced through duct sizing. 
Other systems may be designed with balancing devices 
such as dampers. Dampers provided to balance airflow 
shall be provided with securely fixed minimum- 
position blocking devices to prevent restricting flow 
below the required volume or velocity. 



TABLE 5-1 
Minimum Conveying Velocities 





Feet per iVIinute 


(m/s) 


Vapors, gases, smoke, fumes 


Any 


Fine light dusts, sucii as cotton, iint, and wood fiour (100 mesli and under) 


2,000 


(10.2) 


Dry dusts; powders, such as fine rubber molding power, soap dust 


2,500' 


(12.7)' 


Industrial dusts 

Average dusts, such as sawdust, grinding dust, coal dust 
Heavy dusts, such as metal turnings, lead dusts 
IVIoist dusts and chips, such as lead dust with chips, sticl<y buffing lint, 
quick-lime dust 


3,500 
4,000 

4,500 


(17.8) 
(20.3) 

(22.9) 



Note: 

'The velocity for aluminum and magnesium powder shall be not less than 4,000 feet per minute (20.3 m/s). 



64 



EXHAUST SYSTEMS 



505.3 - 506.2 



505.3 Makeup Air. Makeup air shall be provided to 
replenish air exhausted by the ventilation system. 
Makeup-air intakes shall be located so as to avoid 
recirculation of contaminated air within enclosures^ 

505.4 Hoods and Enclosures. Hoods and 
enclosures shall be used when contaminants 
originate in a concentrated area. The design of the 
hood or enclosure shall be such that air currents 
created by the exhaust systems will capture the 
contaminants and transport them directly to the 
exhaust duct. The volume of air shall be sufficient to 
dilute explosive or flammable vapors, fumes, or 
dusts as set forth in Section 505.2. Hoods of steel 
shall have a base metal thickness not less than 0.027 
inch (0.69 mm) (No. 22 gauge) for Class 1 and Class 5 
metal duct systems; 0.033 inch (0.84 mm) (No. 20 
gauge) for hoods serving a Class 2 duct system; 0.044 
inch (1.12 mm) (No. 18 gauge) for hoods serving a 
Class 3 duct system; and 0.068 inch (1.73 mm) (No. 
14 gauge) for hoods serving a Class 4 duct system. 

Approved nonmetallic hoods and duct systems 
may be used for Class 5 corrosive systems when the 
corrosive mixture is nonflammable. Metal hoods 
used with Class 5 duct systems shall be protected 
with suitable corrosion-resistant material. Edges of 
hoods shall be rounded. The minimum clearance 
between hoods and combustible construction shall 
be the clearance required by the duct system. 

505.12 Pharmacies - Compounding Area of 
Parenterai Solutions. [CA - Board of Ptiarmacy] 

The pharmacy shall have a designated area for the 
preparation of sterile products for dispensing which shall: 

1. Be ventilated in a manner not interfering with 
laminar air flow. 

Note: For additional pharmacy building standard 
requirements, see Chapter 12, California Building 
Code. 

505. 12. 1 Pharmacies - laminar flow biological 
safety cabinet. [CA - Board of Pharmacy] In 

all pharmacies preparing parenteral cytotoxic agents, 
all compounding shall be conducted within a certified 
Class II Type A or Class II Type B vertical laminar 
airflow hood with bag in - bag out design. The 
pharmacy must ensure that contaminated air plenums 
that are under positive air pressure are leak tight. 

Note: Tor additional pharmacy building standard 
requirements, see Chapter 12, California Building Code. 

506.0 Product-Conveying Ducts. 

506.1 Materials. Materials used in product- 
conveying duct systems shall be suitable for the 
intended use and shall be of metal. 

Exceptions: 

(1) Asbestos-cement, concrete, clay, or ceramic 



materials may be used when it is shown that 
these materials will be equivalent to metal 
ducts installed in accordance with this 
chapter. 

(2) Ducts serving a Class 5 system may be 
constructed of approved nonmetallic 
material when the corrosive characteristics 
of the material being conveyed make a 
metal system unsuitable and when the 
mixture being conveyed is nonflammable. 

Approved nonmetallic material shall be 
either a listed product having a flame-spread 
index of twenty-five (25) or less and a smoke- 
developed rating of fifty (50) or less on both 
inside and outside surfaces without evidence 
of continued progressive combustion, or 
shall have a flame-spread index of twenty- 
five (25) or less and shall be installed with 
an automatic fire-sprinkler protection system 
inside the duct. 

(3) Ducts used in central vacuum cleaning 
systems within a dwelling unit shall be 
constructed of materials in compliance with 
the applicable standards referenced in 
Chapter 17. Penetrations of fire walls or 
floor-ceiling or roof-ceiling assemblies shall 
comply with the Building Code. 

Copper or ferrous pipes or conduits 
extending from within the separation 
between a garage and dwelling unit to the 
central vacuuming unit may be used. 

Aluminum ducts shall not be used in systems 
conveying flammable vapors, fumes, or explosive 
dusts, nor in Class 2, 3, or 4 systems. Galvanized 
steel and aluminum ducts shall not be used when the 
temperature of the material being conveyed exceeds 
400°F (205°C). 

Metal ducts used in Class 5 systems that are 
not resistant to the corrosiveness of the product shall 
be protected with appropriate corrosion-resistant 
material. 

506.2 Construction. Ducts used for conveying 
products shall be of substantial airtight construction 
and shall not have openings other than those 
required for operation and maintenance of the 
system. Ducts constructed of steel shall comply with 
Table 5-5 or 5-6. 

Exceptions: 

(1) Class 1 product-conveying ducts that 
operate at less than four (4) inches water 
column (995.6 Pa) negative pressure and 
convey noncorrosive, nonflammable, and 
nonexplosive materials at temperatures not 



65 



506.2 - 506.7 



2007 CALIFORNIA MECHANICAL CODE 



exceeding 250°F (121 °C) may be constructed 
in accordance with Tables 6-1, 6-2, 6-3, 6-4, 
6-5, 6-7, 6-8, or, with prior approval, UMC 
Standard No. 6-2. 

(2) Ducts used in central vacuuming systems 
within a dwelling unit shall be constructed 
of materials in compliance with the 
applicable standards referenced in Chapter 
17. Penetrations of fire-resistive walls, or 
floor-ceiling or roof-ceiling assemblies shall 
comply with the Building Code. Copper or 
ferrous pipes or conduit extending from 
within the separation between a garage and 
dwelling unit to the central vacuum unit 
may be used. 

The use of rectangular ducts conveying 
particulates shall be subject to approval of the 
building official. The design of rectangular ducts 
shall consider the adhesiveness and buildup of 
products being conveyed within the duct. 

Aluminum construction may be used in Class 1 
duct systems only. The thickness of aluminum ducts 
shall be at least two Brown and Sharpe gauges 
thicker than the gauges required for steel ducts set 
forth in Tables 5-5 and 5-6. 

506.3 Fittings. Fittings in Class 2, 3, and 4 systems 
shall be not less than two gauges thicker than the 
thickness required for straight runs. Flexible metallic 
duct may be used for connecting ductwork to 
vibrating equipment. Duct systems subject to wide 
temperature fluctuations shall be provided with 
expansion joints. 

Branches shall connect to main ducts at the large 
end of transitions at an angle not exceeding forty- 
five (45) degrees (0.79 rad). 

Except for ducts used to convey noncorrosive 
vapors with no particulate, accessible cleanouts shall 
be provided at ten (10) foot (3,048 mm) intervals and 
at changes in direction. Access openings shaU also be 
provided for access to sprinklers and other 
equipment within the duct that require servicing. 

506.4 Explosion Venting. Ducts conveying 
explosive dusts shall have explosion vents, openings 
protected by antiflashback swing valves, or rupture 
diaphragms. Openings to relieve explosive forces 
shall be located outside the building. When relief 
devices cannot provide sufficient pressure relief, 
ductwork shall be designed to withstand an internal 
pressure of not less than 100 potinds per square inch 
(689 kPa). 

If a room or building contains a dust explosion 
hazard that is external to protected equipment, as 
defined in 2.2.3.1 of NFPA 654, such areas shall be 



provided with deflagration venting to a safe outside 
location. 

506.5 Supports. Spacing of supports for ducts shall 
not exceed twelve (12) feet (3,658 mm) for eight (8) 
inch (203 mm) ducts nor twenty (20) feet (6,096 mm) 
for larger ducts, -unless justified by the design. 

506.5.1 Duct supports shall be designed to 
carry the weight of the duct half filled with 
material. Where sprinkler protection is provided 
in the duct, the hanger's design shall include the 
weight of the duct half fiOled with water or with 
the material being conveyed, whichever has the 
higher density. Loads shall not be placed on 
connecting equipment. 

Exception: Where adequate drainage is 
provided, the weight of the water shall not 
require consideration. 

506.5.2 Hangers and supports exposed to 
corrosive atmospheres shall be Type 316 SS or 
equivalent. 

506.5.3 To avoid vibration and stress on the 
duct, hangers and supports shall be securely 
fastened to the buUding or structure. 

506.5.4 Hangers and supports shall be designed 
to allow for expansion and contraction. [NFPA 
91:2.5.1 through 2.5.4] 

506.6 Fire Protection. Sprinklers or other 
fire-protection devices shall be installed within 
ducts having a cross-sectional dimension exceeding 
ten (10) inches (254 mm) when the duct conveys 
flammable vapors or fumes. Sprinklers shall be 
installed at twelve (12) foot (3,658 mm) intervals in 
horizontal ducts and at changes in direction. In 
vertical runs, sprinklers shall be installed at the top 
and at alternate floor levels. 

506.7 Duct Clearances. 

506.7.1 All ductwork and system components 
handling combustible material and operating at 
less than 140°F (60°C) shall have a clearance of 
not less than 18 inches (46 cm) from combustible 
construction or any combustible material. 

Exception No. 1: When the ductwork 
system is equipped with an approved 
automatic extinguishing system designed 
for the specific hazard, the clearance shall 
be permitted to be reduced to six (6) 
inches (15 cm) from combustible materials 
and 1/2 inch (13 mm) from combustible 
construction. 

Exception No. 2: When the combustible 
material and construction is protected 



66 



EXHAUST SYSTEMS 



Table 5-2 - 506.7 



TABLE 5-2 
Reduction of Duct Clearance with Specified Forms of Protection 



Cleaiance reduction applied to and covering all combustile surfaces 
with the distance specified as required clearance with no protection 
in 506.7.2 



Minimum Allowable Reduction in Clearance (%) 



Form of Protection 

(a) 3-1 /2 in. (90 mm) thick masonry wall without ventilated airspace 

(b) 1/2 in. (13 mm) thick noncombustile insulation board over 1 in. 

(25.4 mm) glass fiber or mineral wool batts without ventilated airspace 

(c) 0.024 in. (0.61 mm) (No. 24 gauge) sheet metal over 1 in. (25.4 mm) glass 
fiber or mineral wool batts reinforced with wire, or equivalent, on rear face 
with at least a 1 in. (25.4 mm) air gap 

(d) 3-1 /2 in (90 mm) thick masonry wall with at least a 1 in (25.4 mm) air gap 

(e) 0.024 in. (0.61 mm) (No. 24 gauge) sheet metal with at least a 1 in. (25.4 mm) 
air gap 

(f) 1/2 in. (13 mm) thick,noncombustible insulation board with at least a 1 in. 
(25.4 mm) air gap 

(g) 0.024 in. (0.61mm) (No. 24 gauge) sheet metal with ventilated airspace over 
0.024 in. (0.61 mm) (No. 24 gauge) sheet metal with at least a 1 in. (25.4 mm) 
air gap 

(h) 1 in. (25.4 mm) glass fiber or mineral wool batts sandwiched between two 
sheets 0.024 in. (0.61 mm) (No. 24 gauge) sheet metal vwth at least a 1 in. 
(25.4 mm) air gap 



As Wall Protector As Ceiling Protector 



33 
50 

66 



66 
66 

66 

66 

66 



33 
66 

50 
50 
50 

50 



Extent of protection required to reduce clearances from ducts. 



/• Constflietkin using 
J conitxisllfcJ8mat«tel~\ 



Sheet melat or 
otar pnxsctlon 




f 



Cohstruqifon nang 
oambusilble tnaiaid n^ 



Sheet inetel or 
other ptttecWon 



f. 
A 

(Dud \ 

Notes: 

1 , .4a required cleaiancs with no protection 

i, 8= ii$dui:e<t cleaiance penmlElsd 

3. The pmtection appSad to tfie eottstrucllon using oomtxisUtite mateilal shall extend lar enough In each dttectlon <o make C = A 




by the use of materials or products 
listed for protection purposes or in 
accordance with Table 5-2. 

506.7.1.1 Spacers and ties for protection 
materials shall be of noncombustible material 
and shall not be used directly behind the duct. 

506.7.1.2 With all clearance reduction 
systems using a ventilated airspace, air 
circulation shall be provided as described in 
Table 5-2. There shall be at least one (1) inch 
(2.5 cm) between the wall protector and 
combustible walls and ceilings for clearance, 
reduction systems using a ventilated space. 

506.7.1.3 Mineral wool batts (blanket or 



board) shall have a minimum density of 
eight (8) lb./ft.3 (3.6 kq/m^) and have a 
minimum melting point of 1,500°F (816°C). 

506.7.1.4 Insulation board used as a part of 
a clearance-reduction system shall have a 
thermal conductivity of 1 Btu in./ft.^ hr°F 
(0.14 W/m^ hr°C) or less. Insulation board 
shall be formed of noncombustible material. 

506.7.1 .5 There shall be at least one (1) inch 
(2.5 cm) between the duct and the wall 
protector. In no case shall the clearance 
between the duct and the wall surface be 
reduced below that shown in Table 5-2. 

506.7.2 Duct systems operating at elevated 



67 



Table 5-3 



2007 CALIFORNIA MECHANICAL CODE 



TABLE 5-3 
Reduction of Clearances with Specified Forms of Protection 



Where the required clearance with no protection from appliance, vent connector, or 
single-wall metal pipe is: 

36 in. 18 in. 12 in. 9 in. 6 in. 



Type of protection applied 
to and covering all surfaces 
of combustible material 
within the distance specified 
as the required clearance 
with no protection 
[See Figures 9-l(a) 
through 9-l(c)] 



Allowable Clearances with Specified Protection (in.) 

Use Col. 1 for clearances above appliance or horizontal cotuiector. Use Col. 2 for 
clearances from appliances, vertical connector, and single-wall metal pipe. 





Sides 




Sides 




Sides 




Sides 




Sides 




and 




and 




and 




and 




and 


Above 


Rear 


Above 


Rear 


Above 


Rear 


Above 


Rear 


Above 


Rear 


Col.l 


CoL2 


Col.l 


CoL2 


CoLl 


Col. 2 


CoLl 


Col. 2 


CoLl 


Col. 2 



(1)3-1/2 in. thick masonry ~ 24 

wall without ventilated air- 
space 

(2) 1/2 in. insulation board 24 18 
over 1 in. glass fiber or 

mineral wool batts 

(3) 0.024 sheet metal over 18 12 
1 in. glass fiber or mineral 

wool batts reinforced with 
wire on rear face with 
ventilated airspace 

(4) 3-1/2 in. thick masonry ~ 12 
wall with ventilated air 

space 

(5) 0.024 sheet metal with 18 12 
ventilated airspace 

(6) 1 /2 in. thick insulation 18 12 
board with ventilated air- 
space 

(7) 0.024 sheet metal with 18 12 
ventilated airspace over 

0.024 sheet metal with 
ventilated airspace 

(8) 1 in. glass fiber or 18 12 
mineral wool batts 

sandwiched between two 
sheets 0.024 sheet metal 
with ventilated airspace 



12 



12 



6 4 5 3 3 2 

6 4 5 3 3 3 



For SI units, 1 in. = 25.4 mm. 
Notes: 

1 Reduction of clearances from combustible materials shall not interfere with combustion air, draft hood clearance and relief, and accessibility of 
servicing. 

2 All clearances shall be measured from the outer surface of the combustible material to the nearest point on the surface o£ the appliance, disregarding 
any Intervening protection applied to the combustible material. 

3 Spacers and ties shall be of noncombustible material. No spacer or tie shall be used directly opposite the appliance or connector. 

4 Where all clearance reduction systems use a ventilated air space, adequate provision for air circulation shall be provided as described. 
[See Figures 9-l(a) through 9-l(c).] 

5 There shall be at least 1 in. (25 mm) between clearance reduction systems and combustible walls and ceilings for reduction systems using a ventilated 
airspace. 

6 \^ere a wall protector is moimted on a single flat wall away from comers, it shall have a minimum 1 in. (25 mm) air gap. To provide adequate air 
circulation, the bottom and top edges, or only the side and top edges, or all edges shall be left open. 

7 Mineral wool batts (blanket or board) shall have a minimum density of 8 lb. /ft.' (128 kg/ni') and a minimum melting point of 1500°F (816°C). 

8 Insulation material used as part of a clearance reduction system shall have a thermal conductivity of 1.0 Btu in./ft.^ /hr.-°F (0.144 W/m-K) or less. 

9 There shall be at least 1 in. (25 mm) between the appliance and the protector. In no case shall the clearance between the appliance and the combustible 
surface be reduced below that allowed in Table 5-3. 

10 All clearances and thicknesses are minimum; larger clearances and thicknesses are acceptable. 

11 Listed single-wall cotmectors shall be installed in accordance with the terms of their listing and the manufacturer's instructions. 



68 



EXHAUST SYSTEMS 



506.7-507.1 



temperatures above 140°F (60°C) shall have 
clearances from combustible building construc- 
tion or any combustible material of not less than 
eighteen (18) inch (46 cm). 

506.7.3 Where clearance is reduced by using an 
airspace between the combustible wall and the 
wall protector, air circulation shall be provided 
by one of the following methods. 

506.7.3.1 Air circulation shall be permitted 
to be provided by leaving all edges of the 
wall protector open with at least a one (1) 
inch (2.5 cm) air gap. 

506.7.3.2 If the wall protector is mounted 
on a single flat wall away from corners, air 
circulation shall be permitted to be provided 
by one of the following: 

(A) Leaving top and bottom edges open 
to circulation by maintaining the one (1) 
inch (2.5 cm) air gap. 

(B) Leaving top and both side edges 
open to circulation by maintaining the 
(1) inch (2.5 cm) air gap. 

506.7.3.3 Wall protectors that cover two 

walls in a corner shall be permitted to be 
open at the top and bottom edges with at 
least a one (1) inch (2.5 cm) air gap. [NFPA 
91:2.6.1 through 2.6.3.8] 

506.8 Protection from Physical Damage. Ducts 
installed in locations where they are subject to physical 
damage shall be protected by suitable guards. 

506.9 Exhiaust Outiets. Outlets for exhausts that 
exceed 600°F (315°C) shall be in accordance with 
Table 5-7. 

The termination point for exhaust ducts 
discharging to the atmosphere shall be not less than 
the following: 

506.9.1 Ducts conveying explosive or 
flammable vapors, fumes, or dusts: thirty 
(30) feet (9,144 mm) from property line; ten 
(10) feet (3,048 mm) from openings into the 
building, six (6) feet (1,829 mm) from 
exterior walls or roofs; thirty (30) feet (9,144 
mm) from combustible walls or openings 
into the building that are in the direction of 
the exhaust discharge; ten (10) feet (3,048 
mm) above adjoining grade. 

506.9.2 Other product-conveying outlets: 
ten (10) feet (3,048 mm) from property line; 
three (3) feet (914 nun) from exterior wall or 
roof; ten (10) feet (3,048 mm) from openings 
into the building; ten (10) feet (3,048 mm) 
above adjoining grade. 



Part II - Commercial Hoods and Kitchen 
Ventilation 

507.0 General Requirements. 

507.1 Cooking equipment used in processes 
producing smoke or grease-laden vapors shall be 
equipped with an exhaust system that complies with 
all the equipment and performance requirements of 
this standard, and all such equipment and 
performance shall be maintained per this standard 
during all periods of operation of the cooking 
equipment. Specifically, the following equipment 
shall be kept in good working condition: 

(A) Cooking equipment 

(B) Hoods 

(C) Ducts (if applicable) 

(D) Fans 

(E) Fire suppression systems 

(F) Special effluent or energy control equipment 

All airflows shall be maintained. Maintenance 
and repairs shall be performed on all 
components at intervals necessary to maintain 
these conditions. 

507.1.1 All solid-fuel cooking equipment shall 
comply with the requirements of Section 517.0. 

507.1.2 Multiple-tenancy applications shall 
require the concerted cooperation of design, 
installation, operation, and maintenance 
responsibilities by tenants and by the building 
owner. 

507.1.3 All interior surfaces of the exhaust 
system shall be reasonably accessible for 
cleaning and inspection purposes. 

507.1.4 Cooking equipment used in fixed, 
mobile, or temporary concessions, such as 
trucks, buses, trailers, pavilions, tents, or any 
form of roofed enclosure, shall comply with this 
standard unless all or part of the installation is 
exempted by the Authority Having Jurisdiction. 

507.1 .5 Cooking equipment that has been listed 
in accordance with UL 197 or an equivalent 
standard for reduced emissions shall not be 
required to be provided with an exhaust system. 
[NFPA 96: 4.1.1.1] 

507.1.6 The listing evaluation of cooking 
equipment covered by section 507.1.5 shall 
demonstrate that the grease discharge at the 
exhaust duct of a test hood placed over the 
appliance shall not exceed 5 mg/m3 when 
operated with a total airflow of 0.236 cubic 
meters per second (500 dm). [NFPA 96 4.1.1.2] 



69 



507.1 - 507.2 



2007 CALIFORNIA MECHANICAL CODE 



507.1.7 The responsibility for inspection, 
maintenance, and cleanliness of the ventilation 
control and fire protection of the commercial 
cooking operations shall be the ultimate 
responsibility of the owner of the system 
provided that this responsibility has not been 
transferred in written form to a management 
company or other party. [NFPA 96 4.1.5] 

507.2 Clearance. 

507.2.1 Except where enclosures are required, 
hoods, grease removal devices, exhaust fans, 
and ducts shall have a clearance of at least 
eighteen (18) inches (457.2 mm) to combustible 
material, three (3) inches (76,2 mm) to Itmited- 
comibustible m.aterial, and inches (0 mm) to 
noncombustible material. 

Exception No. 1: Where the hood, duct, or 
grease removal device is listed for lesser 
clearances. 

Exception No. 2: Reduced clearance to 
combustible material if the combustible 
material is protected as follows: 

(a) 0.013 inch (0.33 mm) (no. 28 gauge) sheet 
metal spaced out one (1) inch (25.4 mm) on 
noncom.bustible spacers shall have nine 
(9) inch (228.6 mm) clearance to com- 
bustible material. 

(b) 0.027 inch (0.69 mm) (No. 22 gauge) sheet 
metal on one (1) inch (25.4 mm) mineral 
wool batts or ceramic fiber blanket 
reinforced with wire mesh or equivalent 
spaced out one (1) inch (25.4 mm) on non- 
combustible spacers shall have three (3) 
inch (76.2 nun) clearance to combustible 
material. 

Exception No. 3: Reduced clearance to 
limited-combustible materials to zero clearance 
where protected by metal lath and plaster, 
ceramic tile, quarry tile, other noncombtistible 
materials or assembly of noncombustible 
materials, or materials and products that are 
Usted for the purpose of reducing clearance 
and are acceptable to the Authority Having 
Jurisdiction. The listed materials shall be 
installed in accordance with the conditions of 
the listing and the manufacturer's instructions 
and shall be acceptable to the Authority 
Having Jurisdiction. 

507.2.1 .1 Measures shall be taken to prevent 
physical damage to any material or product 
used for the purpose of reducing clearances. 
In the event of damage, the material or 



product shall be repaired and restored to 
meet its intended listing or clearance 
requirements and shall be acceptable to the 
Authority Having Jurisdiction. In the event 
of a fire within a kitchen exhaust system, the 
duct and its enclosure (rated shaft, factory- 
built grease duct enclosure, or field-applied 
grease duct enclosure) shall be inspected by 
qualified personnel to determine whether 
the duct and protection method are 
structurally sound, capable of maintaining 
their fire-protection function, and suitable 
for continued operation. 

507.2.2 The protection methods for ducts to 
reduce clearance shall be applied to the 
combustible or limited-combustible construction, 
not to the duct itself. 

Exception: Field-applied grease duct 
enclosures and factory-built grease duct 
enclosures. 

507.2.3 Field-Applied and Factory Built 
Grease Duct Enclosures. Field-applied grease 
duct enclosures and factory-built grease duct 
enclosures shall listed in accordance with UL 
2221, Standard for Tests of Fire Resistive Grease 
Duct Enclosure Assemblies, or equivalent 
standard and installed in accordance with the 
manufacturer's instructions and the listing 
requirements. [NFPA 96: 4.3.1] 

507.2.4 Field-applied grease duct enclosures 
and factory-built grease duct enclosures shall 
demonstrate that they provide sufficient 
mechanical and structural integrity, resiliency, 
and stability when subjected to expected 
building environmental conditions, duct 
movement imder general operating conditions, 
and duct movement due to fire conditions. 
[NFPA 96: 4.3.2] 

507.2.4.1 Measures shall be taken to prevent 
physical damage to any material or product 
used for the purpose of reducing clearances. 

Exception: When the duct is protected with 
a field-applied grease duct enclosure or 
factory-btult grease duct enclosure. 

507.2.4.2 The specifications of material, | 
gauge, and construction of the duct used in 
the testing and listing of field-applied grease 
duct enclosures and factory-built grease duct 
enclosures shall be included as minimum 
requirements in their listing and installation 
documentation. [NFPA 96: 4.3.3] 

507.2.4.3 The following clearance options | 
for which field-applied grease duct 



70 



EXHAUST SYSTEMS 



507.2 - 508.2 



V / 



enclosures and factory-built grease duct 
enclosures have been successfully evaluated 
shall be clearly identified in their listing and 
installation documentation and on their 
label [NFPA 96: 4.3.4]: 

(1) Open combustible clearance at manufac- 
turer's requested dimensions. [NFPA 
96: 4.3.4(1)] 

(2) Closed combustible clearance at 
manufacturer's requested dimensions, 
with or without specified ventilation. 
[NFPA 96: 4.3.4(2)] 

(3) Rated shaft clearance at manufacturer's 
requested dimensions, with or without 
specified ventilation. [NFPA 96: 4.3.4(3)] 

507.2.5 A duct shall be permitted to contact 
noncombustible floors, interior walls, and other 
noncombustible structures or supports, but it 
shall not be in contact for more than 50 percent 
of its surface area per each lineal foot of contact 
length. Where such direct contact is made, the 
duct shall be protected from corrosion due to 
this contact. 

Exception: When the duct is protected with 
a material or product listed for the purpose 
of reducing clearance to zero. 

507.2.6 Clearances between the duct and 
interior surfaces of enclosures shall meet the 
requirements of Section 507.2. 

507.3 A drawing(s) of the exhaust system installation 
along with a copy of operating instructions for 
subassemblies and components used in the exhaust 



o 



ly-Oven flue 

_, )i duct collar 




FIGURE 5-1 Typical Section of Eyebrow-Type 
Hood. 



system, including electrical schematics, shall be 
available on the premises. 

507.4 If required by the Authority Having 
Jurisdiction, notification in writing shall be given of 
any alteration, replacement, or relocation of any 
exhaust or extinguishing system or part thereof or 
cooking equipment. Satisfaction shall be provided to 
the Authority Having Jurisdiction that the complete 
exhaust system as addressed in this standard is 
installed and operable in accordance with the 
approved design and the manufacturer's instructions. 

508.0 Hoods. 

508.1 Where Required. Hoods shall be installed at or 
above all commercial-type deep fat fryers, broilers, fry 
grills, steam-jacketed kettles, hot-top ranges, ovens, 
barbecues, rotisseries, dishwashing machines, and 
similar equipment that produces comparable amoimts 
of steam, smoke, grease, or heat in a food-processing 
establishment. For the purpose of this section, a food- 
processing establishment shall include any building or 
portion thereof used for the processing of food, but 
shall not inchide a dwelling unit. 

508.1 .1 Construction. The hood or that portion 
of a primary collection means designed for 
collecting cooking vapors and residues shall be 
constructed of and be supported by steel not less 
than 0.043 inch (1.09 mm) (No. 18 MSG) in 
thickness, stainless steel not less than 0.037 
inch(0.94 mm) (No. 20 MSG) in thickness, or 
other approved material of equivalent strength 
and fire and corrosion resistance. 

Exceptions: 

(1) Listed exhaust hoods with or without 
exhaust dampers. 

(2) Type II hoods shall be constructed of at least 
0.024 inch (0.61 mm) (No. 24 gauge) steel. 
Hoods constructed of copper shall be of 
copper sheets weighing at least twenty-four 
(24) ounces per square foot (7.32 kg/m^). 
Joints and seams shall be substantially tight. 
Solder shall not be used except for sealing a 
joint or seam. 

All hoods shall be secured in place [For OSHPD 
1, 2 & 4] to resist the lateral loads given in the 
Califonria Building Code, Title 24, Part 2 by 
noncombustible supports. 

508.2 All seams, joints, and penetrations of the hood 
enclosure that direct and capture grease-laden 
vapors and exhaust gases shall have a liquidtight 
continuous external weld to the hood's lower 
outermost perimeter. Internal hood joints, seams. 



71 



508.2 - 508.4 



2007 CALIFORNIA MECHANICAL CODE 



filter support frames, and appendages attached 
inside the hood need not be welded but shall be 
sealed or otherwise made greasetight. 

Exception No. 1: Penetrations shall be permitted 
to be sealed by devices that are listed for such use 
and whose presence does not detract from the 
hood's or duct's structural integrity. 

Exception No. 2: Eyebrow-type hoods over gas 
or electric ovens shall be permitted to have a duct 
constructed as in Section 510.0 from the oven 
flue(s) cormected to the hood canopy upstream of 
the exhaust plenum as shown in Figure 5-1. The 
duct shall be connected to the hood with a 
continuous weld or have a duct-to-duct 
coimection as shown in Figure 5-6(b) through (d). 

Exception No. 3: Seams, joints, and penetrations 
of the hood shall be permitted to be internally 
welded, provided that the weld is formed 
smooth or ground smooth, so as to not trap 
grease, and is readily cleanable. 

Exception No. 4: Listed exhaust hoods with or 
without exhaust dampers. 

508.3 Insulation materials other than electrical 
insulation shall have a flame-spread rating of 
twenty-five (25) or less when tested in accordance 
with UL 723, Standard for Test for Surface Burning 
Characteristics of Building Materials. Adhesives or 
cements used in the installation of insulating 
materials shall comply with the preceding 
requirements when tested with the specific 
insulating material. 

508.4 Hood Size. Hoods shall be sized according to 
the following calculations and corifigured to provide 
for the capture and removal of grease-laden vapors. 
(See Section 511.2.2.) 

508.4.1 Canopy Size and Location. For 

canopy-type commercial cooking hoods, the 
inside edge thereof shall overhang or extend a 
horizontal distance of not less than sbc (6) inches 
(152 mm) beyond the edge of the cooking 
surface on all open sides, and the vertical 
distance between the lip of the hood and the 
cooking surface shall not exceed four (4) feet 
(1,219 mm). 

Exception: Listed exhaust hoods are to be 
installed in accordance with the terms of 
their listings and the manufacturer's 
installation instructions. 

508.4.1 .1 Capacity of Hoods. Canopy-type 
commercial cooking hoods shall exhaust 
through the hood a minimtun quantity of air 



determined by application of the following 
formulas: 
WHERE: 

A = the horizontal surface area of the hood, in square 
feet (m^). 

P = that part of the perimeter of the hood that is open, in 
feet (mm). 

D = distance in feet (mm) between the lower lip of 
the hood and the cooking surface. 

Q = quantity of air, in cubic feet per minute (L/s). 

When cooking equipment is installed back to back 
and is covered by a common island-type hood, the 
airflow required may be calculated using the 
formula for three sides exposed. Type II hood 
airflow requirements shall be in accordance with the 
requirements for low-temperature appliance hoods. 

508.4.1 .2 The minimum airflow for solid- 
fuel cooking equipment, grease-burning 
charbroUers, and undefined equipment shall 
be: 

Number of Exposed Sides Formula 

4 (island or central hood) Q = 300A 

3 or less Q = 200^1 
Alternate formula Q = lOOPD 

508.4.1 .3 Type I hoods when the cooking 
equipment includes high-temperature 
appliances such as deep-fat fryers: 

Number of Exposed Sides Formula 

4 (island or central hood) Q = 150A 

3 or less Q = lOOA 
Alternate formula Q = lOOPD 

508.4.1.4 Type I hoods where the cooking 
equipment includes medium-temperature 
appliances such as rotisseries, grills, and 
ranges: 

Number of Exposed Sides Formula 

4 (island or central hood) Q = lOQA 
3 or less Q = 75A 
Alternate formula Q = 50PD 

508.4.1.5 Type I hoods where the cooking 
equipment includes low-temperature 
appliances such as medium-to-low- 
temperature ranges, roasters, roasting 
ovens, pastry ovens, and equipment 
approved for use under a Type 11 hood, such 
as pizza overis: 



72 



EXHAUST SYSTEMS 



508.4-509.2 



Number of Exposed Sides Formula 

4 (island or central hood) Q = 75A 

3 or less Q = 50A 

Alternate formula Q = 50PD 

Exception: Listed exhaust hoods are to be 
installed in accordance with the terms of their 
listing and the manufacturer's installation 
instructions. 

508.4.2 Capacity for Noncanopy Hoods. 

In addition to all other requirements for 
hoods specified in this section, the volume 
of air exhausting through a noncanopy-type 
hood to the duct system shall be not less 
than 300 cubic feet per minute per lineal foot 
(465 L/s per m) of cooking equipment. 
Listed noncanopy exhaust hoods and filters 
shall be sized and installed in accordance 
with the terms of their listing and the 
manufacturer's installation instructions. 

Exception: Listed hood assemblies 
designed and installed specifically for the 
intended use. 

508.5 Exhaust Hood Assemblies witli Integrated 
Supply-Air Plenums. 

The construction and size of these hoods shall 
comply with the requirements of Sections 508.1 and 
508.4. 

508.5.1 The construction of the outer shell or the 
inner exhaust shell shall comply with Section 
508.1. If the outer shell is welded, the inner shell 
shall be of greasetight construction. 

508.5.2 A fire-actuated damper shall be installed 
in the supply air plenum at each point where a 
supply air duct inlet or a supply air outlet 
penetrates the continuously welded shell of the 
assembly. The damper shall be listed for such use 
or be part of a listed exhaust hood with or 
without exhaust damper. The actuation device 
shall have a maximum temperature rating of 
286°F (141°C). Supply-air plenums that discharge 
air from the face rather than from the bottom or 
into the exhaust hood and that are isolated from 
the exhaust hood by the continuously welded 
shell extending to the lower outermost perimeter 
of the entire hood assembly shall not require a 
fire-actuated damper. 

508.6 Listed Hood Assemblies. Listed hood 
assemblies shall be installed in accordance with the 
terms of their listing and the manufacturer's 
instructions. 



508.7 Solid-Fuel Hood Assemblies. Where solid- 
fuel cooking equipment is to be used, the solid-fuel 
hood assembly shall comply with Section 517.0. 

508.8 Exhaust Outlets. An exhaust outlet within an 
imlisted hood shall be located so as to optimize the 
capture of particulate matter. Each outlet shall serve 
not more than a twelve (12) foot (3658 mm) section of 
an unlisted hood 

509.0 Grease Removal Devices in Hoods. 

509.1 Grease Removal Devices. Listed grease 
filters, baffles, or other approved grease removal 
devices for use with commercial cooking equipment 
shall be provided. Listed grease filters shall be tested 
in accordance with UL 1046, Grease Filters for 
Exhaust Ducts. Mesh filters shall not be used. 

509.2 Installation. 

509.2.1 The distance between the grease 
removal device and the cooking surface shall be 
as great as possible but not less than eighteen 
(18) inches (457.2 mm). [NFPA 96: 6.2.1.1] 

509.2.2 Where grease removal devices are used 
in conjunction with charcoal or charcoal-type 
broilers, including gas or electrically heated 
charbroilers, a minimum vertical distance of four 
(4) feet (1.22 m) shall be maintained between the 
lower edge of the grease removal device and the 
cooking surface. [NFPA 96: 6.2.1.2] 

Exception No. 1: Grease removal devices 
supplied as part of listed hood assemblies 
shall be installed in accordance with the 
terms of the listing and the manufacturer's 
instructions. [NFPA 96: 6.2.1.5] 

Exception No. 2: For cooking equipment 
without exposed flame and where flue 
gases bypass grease removal devices, the 
minimum vertical distance shall be 
permitted to be reduced to not less than six 
(6) inches (152.4 mm). [NFPA 96: 6.2.1.3]' 

Exception No. 3: Where a grease removal 
device is listed for separation distances less 
than those required in 6.2.1.1 and 6.2.1.2, 
the listing requirements shall be permitted. 
[NFPA 96: 6.2.1.4] 

509.2.3 Grease Removal Device Protection. 

Grease removal devices shall be protected from 
combustion gas outlets and from direct flame 
impingement occurring during normal operation 
of cooking appliances producing high flue gas 
temperatures, such as deep-fat ftyers or upright or 
high broilers (salamander broilers), where the 



73 



509.2 - Figure 5-2 



2007 CALIFORNIA MECHANICAL CODE 



distance between the grease removal device and 
the appliance flue outlet (heat source) is less than 
eighteen (18) inches (457.2 mm). [NFPA 96: 6.2.2.1] 

509.2.3.1 This protection shall be permitted to 
be accomplished by the installation of a steel 
or stainless steel baffle plate between the heat 
sotirce and the grease removal device. [NFPA 
96: 6.2.2.2] 

509.2.3.2 The baffle plate shall be sized and 
located so that flames or combustion gases 
shall travel a distance not less than (eighteen) 
18 inches (457.2 mm) from the heat source to 
the grease removal device. [NFPA 96: 6.2.2.3] 

509.2.3.3 The baffle shall be located not less 
than six (6) inches (152.4 mm) from the grease 
removal devices. [NFPA 96: 6.2.2.4] 

509.2.4 Grease Filters. Grease filters shall be 
listed and constructed of steel or listed 
equivalent material and shall be of rigid 
construction that will not distort or crush under 
normal operation, handling, and cleaning 
conditions. [NFPA 96: 6.2.3.1 and 6.2.3.2] For 
applications listed in Section 111 regulated by the 
Office of State Fire Marshal, grease filters shall be 
Class I when tested' in accordance with the test 
method in Fart 11, Title 24=, Chapter 12-71, SFM 
Standard 12-71-1. 

509.2.4.1 Filters shall be tight fitting and 
firmly held in place and grease filters shall 
be arranged so that all exhaust air passes 
through the grease filters. [NFPA 96: 6.2.3.3] 

509.2.4.2 Filters shall be easily accessible 
and removable for cleaning. [NFPA 96: 
6.2.3.4] 

509.2.4.3 Filters shall be installed at an 
angle not less than 45 degrees from the 
horizontal. [NFPA 96: 6.2.3.5] 

509.2.4.4 [DHS] Grease filters shall be Class 1 
when tested in accordance with the test method 
in SFM 12-71-1. 

509.2.5 Grease Drip Trays. Filters shall be 
equipped with a drip tray beneath their lower 
edges. [NFPA 96: 6.2.4.1] 

509.2.5.1 The tray shall be kept to the 
minimum size needed to collect grease and 
shall be pitched to drain into an enclosed 
metal container having a capacity not 
• exceeding one (1) gallon (3.785 L) [NFPA 96: 
6.2.4.2, and 6.2.4.3]. 

509.2.6 Grease Filter Orientation. Grease filters 
that require a specific orientation to drain grease 



shall be clearly so designated, or the hood shall 
be constructed so that filters cannot be installed 
in the wrong orientation. [NFPA 96: 6.2.5] 

509.3 Solid-Fuel Grease Removal Devices. 

Where solid-fuel cooking equipment is provided 
with grease removal devices, these devices shall 
comply with Section 517.0. 

510.0 Exhaust Duct Systems. 

510.1 General. 

510.1.1 Ducts shall not pass through fire walls 
or fire partitions. 

510.1.2 All ducts shall lead as directly as is 
practicable to the exterior of the building, so as 
not to unduly increase any fibre hazard. 

510.1.3 Duct systems shall not be intercormected 
with any other building ventilation or exhaust 
system. 

510.1.4 All ducts shall be installed without 
forming dips or traps that might collect residues. 
In manifold (common duct) systems, the lowest 
end of the main duct shall be connected flush on 
the bottom with the branch duct. Duct systems 
serving a Type 1 hood shall be so constructed and 
installed that grease cannot become pocketed in 
any portion thereof, and the system shall slope 
not less than 1/4 inch per lineal foot (21 mm/m) 
toward the hood or toward an approved grease 




Hood top 



Perspective 



25.4 mm x 25.4 mm 
(1 in. X 1 in.) angle 
(min), same gauge 
as duct 



(min) • 



Ha 



O.D. of duct 
3.2 mm (VS In.) 
less than I. D. 
of liood collar 



Square, rectangular, 
, or round In shape 

Continuous perimeter weld 
6.4 mm (Va in.) weld studs or 
bolts at each comer and 



^ 



102mm(4in.)(max)Ct^ 



Weld studs or bolts -rr Joint with (SlS-e'C) 1500°F rated 



6.4 mm (Vt in.) 
steel (min) 



gasket or sealant 



Detail of sealed hood-duct joint 

FIGURE 5-2 Permitted Duct-to-Hood Collar 
Connection. 



74 



EXHAUST SYSTEMS 



510.1-510.3 



reservoir. Where horizontal ducts exceed 
seventy-five (75) feet (22,860 mm) in length, the 
slope shall be not less than one (1) inch per lineal 
foot (83 mm/m). 

51 0.1 .5 Openings required for accessibility shall 
comply with Section 510.3. 

510.1.6 A sign shall be placed on all access 
panels stating the following: 

ACCESS PANEL— DO NOT OBSTRUCT 

510.1.7 Duct bracing and supports shall be of 
noncombustible material, securely attached to the 
structure and designed to carry gravity and lateral 
loads within the stress Umitations of the Building 
Code. Bolts, screws, rivets, and other mechanical 
fasteners shall not penetrate duct walls. 



Telescoping duct ]otnt 

\ 



Inside section 



Outside section 



I.D. (mm) 



I.D. (mm) + 6.4 mm 




- Exhaust duct 



- Weld around 



: 50.8 mm (max) 

■^r [2 in. (max)] 



16-gauge [1.6 mm (Vis-ln.)] 
/ black Iron 



Notes: 1. Duct size decreases (going upward) with each telescope. 



2. Smaller (inside) duct section is always above or uphill (on 
sloped duct), to be self-draining into larger (outside) duct. 



Male end 



Female end 



Bell duct Joint 

V — 



I.D. mm 



I.D. mm + 6.4 mm 



(max)' 



I.D. mm 



- Exhaust duct 



£1 



Weld around 



I 50.8 mm (max) 

. [2 In. (max)] 



r- 1 e-gauge [1 .6 mm (Vie-in.)] 



blaol< iron 



Notes: 1. Duct size stays the same throughout the duct system. 

2. Smaller (inside) maia duct end is always above or uphill (on 
sloped duct), to be self-draining into larger (outside) female 
duct end. 



FIGURE 5-3 Telescoping and Bell-Type Duct 
Connections. 



510.1.8 Ducts, Non-Grease. Ducts and 
plenums serving Type II hoods shall be 
constructed of rigid metallic materials as set 
forth in Chapter 6. Duct bracing and supports 
shall comply with Chapter 6. Ducts subject to 
positive pressure shall be adequately sealed. 

510.2 Clearance. 

510.2.1 Clearance between ducts and combustible 
materials shall be provided in accordance with the 
requirements of Section 507.2. 

51 0.2.2 Listed grease ducts shall be installed in 
accordance with the terms of their listings and 
manufacturers' instructions. 

510.3 Openings. 

51 0.3.1 Openings shall be provided at the sides 
or at the top of the duct, whichever is more 
accessible, and at changes of direction. Openings 
shall be protected by approved access panels 
that comply with Section 510.3.4.5. 

Exception: Openings shall not be required 
in portions of the duct that are accessible 
from the duct entry or discharge. 

510.3.2 For hoods with dampers in the exhaust 
or supply collar, an access panel for cleaning and 
inspection shall be provided in the duct or the 
hood collar. This access panel shall be as close to 
the hood as possible but shall not exceed 
eighteen (18) inches (457.2 mm). 

Exception: Dampers that are accessible 
from under the hood. 

510.3.3 Exhaust fans with ductwork connected to 
both sides shall have access for cleaning and 
inspection within three (3) feet (0.92 m) of each side 
of the fan. [NFPA 96: 7.3.7] 

510.3.4 Openings in Ducts. Openings shall | 
conform with Sections 510.3.4.1 through 
510.3.4.5. [NFPA 96: 7.4] 

510.3.4.1 Horizontal Ducts. On horizontal 
ducts, at least one 20 inch by 20 inch (508 
mm by 508 mm) opening shall be provided 
for personnel entry. [NFPA 96: 7.4.1.1] 

510.3.4.1.1 Horizontal ducting shall be | 
secured sufficiently to allow for the weight 
of personnel entry into the duct. Where an 
opening of this size is not possible, openings 
large enough to permit thorough cleaning 
shall be provided at twelve (12) foot (3.7 m) 
intervals. [NFPA 96: 7.4.1.3] 

510.3.4.1.2 Support systems for horizontal 
grease duct systems 609 mm (24 in.) and 
larger in any cross-sectional dimension shall 
be designed for the weight of the ductwork 



75 



510.3-510.7 



2007 CALIFORNIA MECHANICAL CODE 



plus 363 kg (800 lb) at any point in the duct 
systems. [NFPA 96: 7.4.1.3] 

510.3.4.2 On nonlisted ductwork, the edge 
of the opening shall be not less than 1-1/2 
inch (38.1 mm) from all outside edges of the 
duct or welded seams. [NFPA 96: 7.4.1.4] 

510.3.4.3 Vertical Ducts. On vertical 
ductwork where personnel entry is 
possible, access shall be provided at the top 
of the vertical riser to accommodate 
descent. [NFPA 96: 7.4.2.1] 

510.3.4.3.1 Where persormel entry is 
not possible, adequate access for 
cleaning shall be provided on each 
floor. [NFPA 96: 7.4.2.2] 

510.3.4.4 Access Panels. Access panels 
shall be of the same material and thickness 
as the duct (Section 510.5.1). Access panels 
shall have a gasket or sealant that is rated for 
1,500°F (815.6°C) and shall be greasetight. 
Fasteners, such as bolts, weld studs, latches, 
or wing nuts, used to secure the access 
panels shall be carbon steel or stainless steel 
and shall not penetrate duct walls. 

Exception: Listed grease duct access 
door assemblies (access panels) shall be 
installed in accordance with their terms 
of the listings and the manufacturer's 
instructions. 

510.3.4.5 Openings for installation, servicing, 
and inspection of listed fire protection system 
devices and for duct cleaning shall be 
provided in ducts and enclosures and shall 
conform to the requirements of 510.3. 
Enclosure openings required to reach access 
panels in the ductwork shall be large enough 
for the removal of the access panel. 

510.4 Listed Grease Ducts. Listed grease ducts 
shall be installed in accordance with the terms of the 
listing and the manufacturer's instructions. 

510.5 Otiier Grease Ducts. Other grease ducts 
shall comply with the requirements of this section. 

51 0.5.1 iVIateriais. Ducts shall be constructed of 
and supported by carbon steel not less than 
0.054 inch (1.37 mm) (No. 16 MSG) in thickness 
or staiiUess steel not less than 0.043 inch (1.09 
mm) (No. 18 MSG) in thickness. 

510.5.2 Instaiiation. 

510.5.2.1 All seams, joints, penetrations, 
and duct-to-hood collar connections shall 
have a liquidtight continuous external weld. 



Exception No. 1: Duct-to-hood collar 
connections as shown in Figtire 5-2 shall 
be permitted. 

Exception No. 2: Penetrations shall be 
permitted to be sealed by Other listed 
devices that are tested to be greasetight 
and are evaluated under the same 
conditions of fire severity as the hood or 
enclostire of listed grease extractors and 
whose presence does not detract from 
the hood's or duct's structural integrity. 

Exception No. 3: Internal welding shall 
be permitted, provided the joint is 
formed or groxmd smooth and is readily 
accessible for inspection. 

510.5.2.2 Overlapping duct connections of 
either the telescoping or the bell type shall 
be used for welded field joints, not butt- 
weld connections. The inside duct section 
shall always be uphill of the outside duct 
section. The difference between inside 
dimensions of overlapping sections shall not 
exceed 1/4 inch (6.4 mm). The overlap shall 
not exceed two (2) inches (50.8 mm). (See 
Figure 5-3.) 

510.6 Exterior installations. 

510.6.1 The exterior portion of the 
ductwork shall be vertical wherever possible 
and shall be installed and adequately 
supported on the exterior of a building. 
Bolts, screws, rivets, and other mechanical 
fasteners shall not penetrate duct walls. 
Clearance of any ducts shall comply with 
Section 507.2. 

510.6.2 All ducts shall be protected on the 
exterior by paint or other suitable weather- 
protective coating or shall be constructed of 
noncorrosive stainless steel. Ductwork 
subject to corrosion shall have minimal 
contact with the building surface. 

510.7 interior installations. 

51 0.7.1 In all buildings more than one story in 
height, and in one-story buildings where the roof- 
ceiling assembly is required to have a fire 
resistance rating, the ducts shall be enclosed in a 
continuous enclosure extending from the lowest 
fire-rated ceiling or floor above the hood, through 
any concealed spaces, to or through the roof so as 
to maintain the integrity of the fire separations 
required by the applicable Building Code 
provisions. The enclosure shall be sealed aroimd 
the duct at the point of penetration of the lowest 



76 



EXHAUST SYSTEMS 



510.7- Figure 5-4 



fire-rated ceiling or floor above the hood in order 
to maintain the fire resistance rating of the 
enclosure and shall be vented to the exterior of the 
btiilding through weather-protected openings. 

Exception: The continuous enclosure 
provisions shall not be required where a field- 
applied grease duct enclosure or a factory- 
built grease duct enclosure (see Section 
507.2.3) is protected with a listed duct- 
through-penetration protection system 
equivalent to the fire resistance fating of the 
assembly being penetrated, and the materials 
are installed in accordance with the conditions 
of their listings and the manufacturers' 
instructions and are acceptable to the 
Authority Having Jurisdiction. 

For applications listed in Section 111 regulated by the 
Office of the State Fire Marshal, see Section 510.7.1.1. 

510.7.1.1 [For SFM] A grease duct serving a 
Type I hood which penetrates a ceiling, wall or floor 
shall be enclosed in a duct enclosure from the point 
of penetration. A duct may only penetrate exterior 
walls at locations where unprotected openings are 
permitted by the building code. Duct enclosures 
shall be constructed in accordance with the 
California Building Code. Duct enclosures shall be 
of a least one-hour fire resistive construction in all 
buildings and shall be of two-hour fire-resistive 
construction in Types I and II fire-resistive 
buildings. The duct enclosure shall be sealed 
around the duct at the point of penetration and 
vented to the exterior through weather protected 
openings. The enclosure shall be separated from the 
duct by at least three (5) inches (76mm) and not 
more than twelve (12) inches (305mm) and shall 
serve as single grease exhaust duct system. 

510.7.2 The enclosure required in Sfection 510.7.1 
shall conform to Sections 510.7.2.1 through 510.7.2.3. 

510.7.2.1 If the building is less than four stories 
in height, the enclosure wall shall have a fire 
resistance rating of not less than one (1) hour. 

510.7.2.2 If the building is four stories or more 
in height, the enclosure wall shall have a fire 
resistance rating of not less than two (2) hours. 

510.7.2.3 Clearance from the duct or the exhaust 
fan to the interior surface of enclosures of 
combustible construction shall be not less than 
eighteen (18) inches (457.2 mm), and clearance 
frorri the duct to the interior surface of enclosures 
of noncombustible or limited-combustible 
construction shall be not less than six (6) inches 
(152.4 mm). Provisions for reducing clearances as 



described in Section 507.2 are not applicable to 
enclosures. 

Exception: Clearance from the outer surfaces 
of field-applied grease duct enclosures and 
factory-built grease duct enclosures to the 
interior surfaces of construction installed 
around them shall be permitted to be 
reduced where the field-applied grease duct 
enclosure materials and the factory-built 
grease duct enclosures are installed in 
accordance with the conditions of their 
listings and the manufacturers' instructions 
and are acceptable to the Authority Having 
Jurisdiction. 

510.7.3 For field-applied grease duct enclosures 
and factory-built grease duct enclosures, the 
materials and products shall conform to Sections 
510.7.3.1 through 510.7.3.3. 

510.7.3.1 Field-applied grease duct 
enclosures and factory-built grease duct 
enclosures shall demonstrate that they 
provide sufficient mechanical and structural 



3.8 m 






3m 

(10 ft):;- 




3m 
(10 ft) 



L 3m J 

r* — (10 ft) — H 



_rr-|_Hoi1zonta[ 
FAI 



FAI 



Grade 



Notes: 1. i=resh air intake (FAI) 'applies to any air Intake, Including an 
operable door or window. 
2. Example: 
FAI Is same plane as extiaust or lower: 3 m [1 ft (min)] 
between closest edges. 

FAI above plane of exhaust: 3 m + .076 m (10 ft + 0.25 ft) per 
degree between closest edge 

FIGURE 5-4 Exhaust Termination Distance from 
Fresh Air Intalce (FAI) or Operable Door or 
Window. 



77 



510.7- Figure 5-6(b) 



2007 CALIFORNIA MECHANICAL CODE 



integrity, resiliency, and stability when 
subjected to expected btulding environmental 
conditions, duct movement under general 
operating conditions, and duct movement 
due to interior and exterior fire conditions. 

51 0.7.3.2 Measures shall be taken to prevent 
physical damage to any covering or 
enclosure material. Any damage to the 
covering or enclosure shall be repaired and 
the covering or enclosture restored to meet its 
intended listing and fire-resistive rating and 
to be acceptable to the Authority Having 
Jurisdiction. 

510.7.3.3 In the event of a fire within a kitchen 
exhaust system, the duct, the enclosure, or the 
covering directly applied to the duct shall be 
inspected by qualified personnel to determine 
whether the duct, the enclosure, and the 
covering directly applied to the duct are 
structurally sound, capable of maintaining 
their fire protection functions, suitable for 
continued operation, and acceptable to the 
Authority Having Jurisdiction. 

510.7.4 For listed grease ducts, see Section 510.4. 

510.7.5 If openings in the enclosure walls are 
provided, they shall be protected by approved 
self-closing fire doors of proper rating. Fire 
doors shall be installed in accordance with 
NFPA 80, Standard for Fire Doors and Fire 
Windows. Openings on other listed materials or 
products shall be clearly identified and labeled 
according to the terms of the listing and the 
manufacturer's instructions and shall be 
acceptable to the Authority Having Jurisdiction. 
The panels shall be readily accessible. 

510.7.6 Each duct system shall constitute an 
individual system serving only exhaust hoods in 
one fire zone on one floor. Multiple ducts shall 
not be permitted in a single enclosure unless 
acceptable to the Authority Having Jurisdiction. 

510.8 Termination of Exhaust System. 

510.8.1 The exhaust system shall terminate as 
follows: 

(A) Outside the building with a fan or duct. 

(B) Through the roof, or to the roof from 
outside, as in Section 510.8.2, or through a 
wall, as in Section 510.8.3. 

510.8.2 Rooftop Terminations. 

51 0.8.2.1 Rooftop terminations shall be 
arranged with or provided with the 
following: 




-0.46m(min) 
[18in. (min)] 



- Roof curb 



Outside air intal<e -I 

FIGURE 5-5 Upblast Fan Clearances. 



Flanges to be positioned 
so that the gasket Is 
protected from direct 
contact with grease 



j\Ci 



-H U- 



815.6°C (1500°F) 
^rated gasket 

Minimum 

25.4x25.4x3.2 mm 
(1 in. X 1 1n. X % In.) 
angle flange 



6.4 mm OA-in.) carbon 
steel of stainless steel 
bolts 102 mm (max) 
[4 in. (max)] - 
on center 



12.8 mm (min) , 
[V4ln.(min)l 



Continuous 
perimeter 
weld (typ.) 



• Lock washer 



Unassembled position 



Assembled position 



FIGURE 5-6(a) Typical Section of Duct-to-Fan 
Connection — Butt Joint Method. 



Flanges to be positioned 
so that the gasket is 81 5.6°C (1 SOCF) 
protected from direct rated gasket 
contact with grease / ... , 

/ Minimum 



J\ 



25.4 X 25.4 X 3.2 mm 
(1 in. X 1 in. X V6 in.) 
angle flange 



6.4-mm (Vi-in.) carbon 
steel or stainless steel 
bolts 102 mm (max);? 
[4 in. (max)] 
on center 



Airflow 



12.8 mm (min) 
\[14ln.(mln)]-»| 



r 



V 

Continuous 
perimeter 
weld (typ.) 



Lock washer 



Unassembled position 



Assembled position 



FIGURE 5-6(b) Typical Section of Duct-to-Fan 
Connection-^Overlapping Method. 



78 



EXHAUST SYSTEMS 



Figure 5-6(c)- 510.8 



815.6''C(1500°F) 
rated sealant 



I, 




6.4-mm (Vi-in.) carbon 
steel or stainless steel 
bolts 102 mm (max) ■ 
[4 In, (max)] - 
on center 



MInlmurn 25.4-mm 
(1 -In.) flange 




■ Look washer 
Unassembled position 



Assembled position 



FIGURE 5-6(c) Typical Section of Duct-to-Fan 
Connection^Sealant IViethod. 



815.6°C(1500''F) 
rated gasket 



Lock waslier 




6.4-mm (Vi-in.) carbon 
steel or stainless steel 
weld studs 102 mm (max) 
[4 in. (max)] 
on center 



(Minimum 

25.4 X 25.4 X 3.2 mm 
(1 In. X 1 1n. X 14 In.) 
angle flange 



Continuous 

perimeter 

weld 




Unassembled position 



Assembled position 



FiGURE 5-6(d) Typicai Section of Duct-to-Fan 
Connection — Direct to Fan Inlet Cone Method. 

(A) A minimum of ten (10) feet (3.05 iri) of dearahce 
from the outlet to adjacent buildings^ 
property lines, and air intakes. Where space 
limitations absolutely prevent a ten (10) foot 
(3.05m) horizontal separation from an air 
intake, a vertical separation shall be permitted, 
with the exhaust outlet being a minimum of 
three (3) feet (0.92 m) above any air intake 
located within ten (10) feet (3.05 m) 
horizontally. 

(B) The exhaust flow directed up and away 
from the surface of the roof and a minimum 
of forty (40) inches (1.02 m) above the roof 
surface. 

(C) The ability to drain grease out of any traps 
or low points formed in the fan or duct near 
the- termination of the system into a 
collection container that is noncombustible, 
closed, rainproof, structurally sound for the 
service to. which it is applied, and will not 
sustain combustion. A grease collection 



device that is applied to exhaust systems 
shall not inhibit the performance of any fan. 

Exception: Grease containers that are 
evaluated for equivalency with the 
preceding requirements and listed as 
such. 

(D) A listed grease duct complying with Section 
510.4, or with ductwork complying with 
Section 510.5. 

(E) A hinged upblast fan supplied with flexible 
weatherproof electrical cable and service 
hold-open retainer to permit proper 
inspection and cleaning that is listed for 
commercial cooking equipment, provided 
the ductwork extends a minimum of 
eighteen (18) inches (457.2 mm) above the 
roof surface and the fan discharges a 
minimum of forty (40) inches (1.02m) 
above the roof surface. (See Section 511.1.1.) 

(F) Other approved fan, provided (1) it meets 
the requirements of Sections 510.8.2(C) and 
511.1.3, and (2) its discharge or its extended 
duct discharge meets the requirements of 
Section 510.8.2(B). 

510.8.2.2 Listed flexible connectors may be 
used on exterior roof locations when 
required for proper equipment vibration 
isolation. 

51 0.8.2.3 Fans shall be provided with safe 
access and a work surface for inspection and 
cleaning. 

510.8.3 Wall Terminations. 

510.8.3.1 Wall terminations shall be 

arranged with or provided with the 

following properties: 

(A) Through a noncombustible wall with a 
minimum of ten (10) feet (3.05 m) of 
clearance from the outlet to adjacent 
buildings, property lines, grade level, 
combustible construction, or electrical 
equipment or lines, and the closest 
point of any air intake or operable door 
or window at or below the plane of the 
exhaust termination. The closest point 
of any air intake or operable door or 
window above the plane of the exhaust 
termination shall be a minimum of ten 
(10) feet (3.05 m) distant, plus 0.25 feet 
(0.076m) for each 1 degree from horizontal, 
the angle of degree being measured 
from the center of the exhaust termination 
to the center of the air intake or operable 
door or window. (See Figure 5-4.) 

Exception: A wall termination in a 



79 



510.8-511.2 



2007 CALIFORNIA MECHANICAL CODE 



secured area can be at a lower 
height above grade if acceptable to 
the Authority Having Jurisdiction. 

(B) The exhaust flow directed perpendicularly 
outward from the wall face or upward. 

(0) All the ductwork pitched to drain the 
grease back into the hood(s), or with a 
drain provided to bring the grease back 
into a container within the building or 
into a remote grease trap. 

(D) A listed grease duct complying with 
Section 510.4, or other ducts complying 
with Section 510.5. 

(E) An approved fan, provided it meets the 
requirements of Sections 510.8.3.1(C) 
and 511.1.1 or 511.1.3. 

510.9 Solid-Fuel Duct Systems. Where solid-fuel 
cooking equipment is to be vented, the duct system 
shall comply with Section 517.0. 

51 1 .0 Air IVIovement. 

511.1 Exhaust Fans for Commercial Cooking 
Equipment. 

Where solid-fuel cooking equipment is to be vented, 
the duct system shall comply with Section 517.0. 

511.1.1 Approved upblast fans with motors 
surrounded by the airstream shall be hinged, 
supplied with flexible weatherproof electrical 
cable and service hold-open retainers, and listed 
for this use. (See Figure 5-5.) Installation shall 
conform to the requirements of Section 510.8. 

511.1.2 In-Line Exhaust Fans. 

511.1.2.1 In-line fans shall be of the type 
with the motor located outside the airstream 
and with belts and pulleys protected from 
the airstream by a greasetight housing. 
They shall be connected to the exhaust duct 
by flanges securely bolted as shown in 
Figure 5-6(a), or by a system specifically 
listed for such use. Flexible connectors shall 
not be used. 

51 1 .1 .2.2 If the design or positioning of the 
fan allows grease to be trapped, a drain 
directed to a readily accessible and visible 
grease receptacle, not exceeding one (1) 
gallon (3.8 L), shall be provided. In-line 
exhaust fans shall be located in an easily 
accessible area of adequate size to allow for 
service or removal. If the duct system 
connected to the fan is in an enclosure, the 
space or room in which the exhaust fan is 



located shall have the same fire resistance 
rating as the enclosure. 

51 1 .1 .3 Utility set exhaust fans, if installed at the 
rooftop termination point, shall meet the 
requirements of Section 510.8.2.1(A) through 
Section 510.8.2.2. If the fan is installed within the 
building, it shall be located in an easily accessible 
area of adequate size to allow for service or 
removal. If the duct system connected to the fan is 
in an enclosure, the space or room in which the 
exhaust fan is located shall have the same fire 
resistance rating as the enclosure. The fan shall be 
connected to the exhaust duct by flanges securely 
bolted as shown in Figures 5-6(a) through 5-6(d) 
or by a system specifically listed for such use. 
Flexible connectors shall not be used. Exhaust 
fans shall have a drain directed to a readily 
accessible and visible grease receptacle not to 
exceed one (1) gallon (3.8 L). 

511.1.4 Exhaust fan housings shall be 
constructed of carbon steel not less than 0.054 
inch (1.37 mm) (No. 16 MSG) in thickness or 
stainless steel not less than 0.043 inch (1.09 mm) 
(No. 18 MSG) in thickness or, if listed, 
constructed in accordance with the terms of the 
listing. 

511.1.5 Openings for cleaning, servicing, and 
inspection shall conform to the requirements of 
Section 510.3.3 Clearances shall conform to the 
requirements of Sections 507.2, or 510.7.2.3 if 
installed within an enclosure. 

51 1 .1 .6 All wiring and electrical equipment shall 
comply with the California Electrical Code. 

511.2 Airflow. 

51 1 .2.1 The air velocity through any duct shall 
be not more than 2,500 feet (457.2 m) per minute. 

Exception: Transition duct sections shall be 
permitted to be cormected to hoods and exhaust 
fans that do not meet this velocity, provided that 
they do not exceed three (3) feet (0.92 m) in 
length and do not contain traps for grease. 

51 1 .2.2 Exhaust-air volumes for hoods shall be 
of sufficient level to provide for capture and 
removal of grease-laden cooking vapors. Test 
data, performance acceptable to the Authority 
Having Jurisdiction, or both, shaU be provided, 

displayed, or both, upon request. 

Exception: Lower exhaust-air volumes shall 
be permitted during no-load cooking 
conditions, provided they are sufficient to 
capture and remove flue gases and residual 
vapors from cooking equipment. 



80 



EXHAUST SYSTEMS 



511.2-512.3 



51 1 .2.3 A hood exhaust fan(s) shall continue to 
operate after the extinguishing system has been 
activated, unless fan shutdown is required by a 
listed component of the ventilation system or by 
the design of the extinguishing system. It shall 
not be required to restart the hood exhaust fan 
when the extinguishing system is activated if the 
exhaust fan and all cooking equipment served 
by the fan had previously been shut down. 

51 1 .3 Replacement Air. Replacement air quantity 
shall be adequate to prevent negative pressures in the 
commercial cooking area(s) from exceeding 0.02 inch 
water coltmm (4.98 kPa). 

Exceptions: 

(1) When its fire-extinguishing system 
discharges, makeup air supplied 
internally to a hood shall be shut off. 

(2) Compensating hoods shall meet the 
airflow requirements specified in 
Sections 508.4.1.3 through 508.4.1.5. 
Compensating hoods shall extract at 
least 20 percent of their required exhaust 
airflow from the kitchen area. 

511.4 Common Duct (Manifold) Systems. 

51 1 .4.1 Master kitchen exhaust ducts that serve 
multiple tenants shall include provision to bleed 
air from outdoors or from adjacent spaces into the 
master exhaust duct where required to maintain 
the necessary minimum air velocity in the master 
exhaust duct. 

51 1 .4.2 This bleed-air duct shall cormect to the 
top or side of the master exhaust duct. 

511.4.3 The bleed-air duct shall have a fire 
damper at least twelve (12) inches (304.8 mm) 
from the exhaust duct connection. 

51 1 .4.4 The bleed-air duct shall have the same 
construction and clearance requirements as the 
main exhaust duct from the connection to the 
exhaust duct to at least twelve (12) inches (304.8 
mm.) on both sides of the fire damper. 

51 1 .4.5 Each bleed air duct shall have a means 
of adjusting (e.g., using volume dampers) the 
bleed-air quantity. 

51 1 .4.6 Such means shall be installed in between 
the fire damper and the source of bleed air. 

51 1 .4.7 A bleed air duct shall not be used for the 
exhaust of grease-laden vapors and shall be so 
labeled. 

511.4.8 Unused tenant exhaust connections to 
the master exhaust duct that are not used as 
bleed air connections shall be disconnected and 
sealed at the main duct. 



511.5 Solid-Fuel Air Movement Requirements. Where 
solid-fuel cooking equipment is used, exhaust and 
replacement air also shall comply with Section 517.0. 

512.0 Auxiliary Equipment. 

512.1 Dampers. Dampers shall not be installed in 
exhaust ducts or exhaust duct systems. 

Exception: Where specifically listed for such use 
or where required as part of a listed or approved 
device or system. 

512.2 Electrical Equipment. 

512.2.1 Wiring systems of any type shall not be 
installed in ducts. 

512.2.2 Motors, lights, and other electrical 
devices shall not be installed in ducts or hoods 
or located in the path of travel of exhaust 
products. 

Exception: Where specifically approved for 
such use. 

51 2.2.3 Lighting units in hoods shall be listed 
for use over commercial cooking appliances 
and installed in accordance with the terms of 
their listing. 

512.2.4 Lighting units on hoods shall not be 
located in concealed spaces. 

Exceptions: 

(1) Where part of a listed exhaust hood. 

(2) Where specifically listed for such use 
and installed in accordance with the terms 
of the listing. 

51 2.2.5 All electrical equipment shall be installed 
in accordance with the California Electrical Code, 
with due regard to the effects of heat, vapor, and 
grease on the equipment. 

512.3 Otiier Equipment. 

512.3.1 Fume incinerators, thermal recovery 
units, air pollution control devices, or other 
devices shall be permitted to be installed in 
ducts or hoods or located in the path of travel of 
exhaust products where specifically approved 
for such use. Downgrading other parts of the 
exhaust system due to the installation of these 
approved devices, whether listed or not, shall 
not be allowed. 

512.3.2 Any equipment, listed or otherwise, that 
provides secondary filtration or air pollution 
control and that is installed in the path of travel of 
exhaust products shall be provided with an 
approved automatic fire-extingtushing system for 
the protection of the component sections of the 
equipment and shall include protection of the 
ductwork downstream of the equipment, whether 
or not the equipment is provided with a damper. 



81 



512.3-513.2 



2007 CALIFORNIA MECHANICAL CODE 



If the equipment can be a source of ignition, it 
shall be provided with appropriate detection to 
operate the fire-extinguishing system. 

512.3.3 Where a cooking exhaust system 
employs an air pollution control device that 
recirculates air into the building, the provisions 
of Section 516.0 shall apply. 

512.4 Solid-Fuel Auxiliary Equipment. Where solid- 
fuel cooking comprises any part of a cooking operation, 
additional provisions and equipment as described in 
Section 517.0 shall be used where reqtiired. 

513.0 Fire-Extinguisliing Equipment. 

513.1 General Requirements. 

513.1.1 Fire-extinguishing equipment for the 
protection of grease removal devices, hood 
exhaust plenums, and exhaust duct systems 
shall be provided. 

513.1.2 Cooking equipment that produces 
grease-laden vapors (such as, but not limited to, 
deep-fat fryers, ranges, griddles, broUers, woks, 
tilting skillets, and braising pans) shall be 
protected by fire-extinguishing equipment. 

513.2 Types of Equipment. 

513.2.1 Fire-extinguishing equipment shall 
include both automatic fire-extinguishing 
systems as primary protection and portable fire 
extinguishers as secondary backup. [NFPA 
96:10.2.1] ■ 

51 3.2.1 .1 A placard identifying the use of 
the extinguisher as secondary backup means 
to the automatic fire suppression system 
shall be conspicuously placed near each 
portable fire extinguisher in the cooking 
area. [NFPA 96:10.2.2] 

51 3.2.2 Commercial cooking equi-pment that produce 
grease laden vapors shall be provided with a Type I 
Hood, in accordance with this Code, and an 
automatic fire extinguisher system that is listed and 
labeled for its intended use as follows: 

1. Wet chemical extinguishing system (NFPA 17 A, 
Standard for Wet Chemical Extinguishing 
Systems), complying with UL 300. 

2. Carbon dioxide extinguishing systems (NFPA 
12, Standard on Carbon Dioxide Extinguishing 
Systems), 

3. Automatic fire sprinkler systems (NFPA 13, 
Standard for the Installation of Sprinkler 
Systems). 

All existing dry chemical and wet chemical extinguishing 
systems shall comply with UL 300, no later than the 
second required servicing of the system following the 
effective date of this section. 



Exception 1: Automatic fire-extinguishing 
equipment provided as part of listed 
recirculating systems complying with 
standard UL 197, Standard for Safety- 
Commercial Electric Cooking Appliances. 
[NFPA 96:10.2.5] 

Exception 2; Public schools, kitchens, without 
deep-fat fryers, shall be upgraded to a UL 300 
compliant system during state funded 
modernization projects that are under the 
jurisdiction of the Division of the State Architect. 

513.2.3 In existing systems, when changes in the 
cooking media, positioning, or replacement of 
cooking equipment occur, the fire-extinguishing 
system shall be made to comply with 513.2.2. 
[NFPA 96 10.2.3.1] 

513.2.4 Modification of Existing Hood 
Systems 

51 3.2.4.1 Any abandoned pipe or conduit 
from a previous installation shall be 
removed from within the hood, plenum, 
and exhaust duct. [NFPA 96 10.2.7.1] 

513.2.4.2 Penetrations and holes resulting 
from the removal of conduit or piping shall 
be sealed with listed or equivalent liquid 
tight sealing devices. [NFPA 96 10.2.7.2] 

51 3.2.4.3 The addition of obstructions to 
spray patterns from the cooking appliance 
nozzle(s) such as baffle plates, shelves, or 
any modification shall not be permitted. 
[NFPA 96 10.2.7.3] 

513.2.4.4 Changes or modifications to the 
hazard after installation of the fire- 
extinguishing systems shall result in 
reevaluation of the system design by a 
properly trained and qualified person(s) or 
company. [NFPA 96 10.2.7.4] 

513.2.5 Fixed Baffle Hoods with Water Wash. | 

Grease removal devices, hood exhaust plenums, 
and exhaust ducts requiring protection in 
accordance with Section 513.1.1 shall be 
permitted to be protected by a listed fixed baffle 
hood containing a constant or fire-actuated 
water-wash system that is listed and in 
compliance with UL 300 or other equivalent 
standards and shll be installed in accordance 
with the requirements of their listing. [NFPA 96: 
10.2.8.1] 

513.2.5.1 The water for listed, fixed baffle I 
hood assemblies shall be permitted to be 
supplied from the domestic water supply 
when the minimum water pressure and 
flow are provided in accordance with the 
terms of the listing. [NFPA 96: 10.2.8.3] 

513.2.5.2 The water supply shall be I 



82 



EXHAUST SYSTEMS 



513.2-513.9 



monitored by an annunciated low water 
pressure switch. 

513.2.5.3 The water wash in the fixed baffle 
hood shall be activated by the cooking 
equipment extinguishing system. 

513.3 Simultaneous Operation. Fixed-pipe 
extinguishing systems in a single hazard area shall 
be arranged for simultaneous automatic operation 
upon actuation of any one of the systems. 

Exception No. 1: Where the fixed-pipe 
extinguishing system is an automatic sprinkler 
system. 

Exception No. 2: A dry or wet chemical system 
shall be permitted to be used to protect common 
exhaust ductwork by the methods specified in 
NFPA 17A, Standard for Wet Chemical 
Extinguishing Systems, in lieu of simultaneous 
automatic operation. 

513.4 Fuel Shutoff. 

513.4.1 Upon activation of any fire-extinguishing 
system for a cooking operation, aU sources of fuel 
and electric power that produce heat to all 
equipment requiring protection by that system 
shall automatically shut off. 

Exception No. 1: Steam supplied from an 
external source. 

Exception No. 2: Solid-fuel cooking operations. 

513.4.2 Any gas appliance not requiring 
protection, but located under the same ventila- 
ting equipment, shaU also automatically shut off 
upon activation of any extinguishing system. 

513.4.3 Shutoff devices shall require manual reset. 

513.5 Manual Activation. 

513.5.1 A readily accessible means for manual 
activation shall be locaited between forty-two (42) 
inches and sixty (60) inches (1,067 mm and 1,524 
mm) above the floor, located in a path of exit or 
egress, and clearly identify the hazard protected. 
The automatic and manual means of system 
activation external to the control head or releasing 
device shall be separate and independent of each 
other so that failure of one will not impair the 
operation of the other. 
Exceptions: 

(1) The manual means of system activation 
shall be permitted to be common with 
the automatic means if the manual 
activation device is located between the 
control head or releasing device and the 
first fusible link. 

(2) An automatic sprinkler system. 



513.5.2 The means for manual actuator(s) shall 
be mechanical and shall not rely on electrical 
power for actuation. 

Exception: Electrical power shall be 
permitted to be used for manual activation if 
a standby power supply is provided or if 
supervision is provided as per 513.7.1. 

513.6 System Annunciation. 

513.6.1 Upon activation of an automatic fire- 
extinguishing system, an audible alarm or visual 
indicator shall be provided to show that the 
system has activated. 

513.6.2 Where a fire alarm signaling system is 
serving the occupancy where the extinguishing 
system is located, the activation of the automatic 
fire-extinguishing system shall activate the fire 
alarm signaling system. 

513.7 System Supervision. 

513.7.1 Where electrical power is required to 
operate the automatic fire-extinguishing system, 
it shall be monitored by a supervisory alarm, 
with a standby power supply provided. 

Exceptions: 

(1) Where automatic fire-extinguishing 
systems include automatic mechanical 
detection and actuation as a backup 
detection system. 

(2) Where fire-extinguishing systems are 
intercormected or interlocked with the 
cooking equipment power sotirces so that 
if the fire-extinguishing system becomes 
inoperable due to power failtire, all sources 
of fuel or electric power that produce heat 
to all cooking equipment serviced by that 
hood shall automatically shut off. 

513.8 Special Design and Application. 

513.8.1 Hoods containing automatic fire- 
extinguishing systems are protected areas; 
therefore, these hoods are not considered 
obstructions to overhead sprinkler systems and 
shall not require floor coverage imderneath. 

513.8.2 A single listed detection device shall be 
permitted for more than one appliance when 
installed in accordance with the terms of the listing. 

513.9 Review and Certification. 

513.9.1 Where required, complete drawings of 
the system installation, including the hood(s), 
exhaust duct(s), and appliances, along with the 
interface of the fire-extinguishing system 
detectors, piping, nozzles, fuel shutoff devices, 
agent storage container(s), and manual actuation 
device(s), shall be provided. I 



83 



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2007 CALIFORNIA MECHANICAL CODE 



513.9.2 Installation of systems shall be 
performed only by persons properly trained and 
qualified to install the specific system being 
provided. The installer shall provide certification 
that the installation is in agreement with the 
terms of the listing and the manufacturer's 
instructions and /or approved design. 

513.10 Portable Fire Extinguishers. 

513.10.1 Portable fire extinguishers shall be 
installed in kitchen cooking areas in accordance 
with Chapter 3, Title 19 California Code of 
Regulations. Such extinguishers shall use agents 
that saponify upon contact with hot grease, such 
as sodium bicarbonate and potassium bicar- 
bonate dry chemical and potassium carbonate 
solutions. Class B gas-type portables such as CO2 
and halon shall not be permitted in kitchen 
cooking areas. Manufacturer's recommendations 
shall be followed. 

513.10.1.1 Portable fire extinguishers listed 
specifically for use in the kitchen cooking 
areas shall also be permitted. 

513.10.2 Other fire extinguishers in the kitchen 
area shall be installed in accordance with Chapter 
3, Title 19 California Code of Regulations. 

513.11 Solid-Fuel Fire-Extinguishing Equipment. 

Where solid-fuel cooking equipment is served by fire- 
extinguishing equipment, the provisions of Section 
517.0 shall apply. 

514.0 Procedures for the Use and Maintenance of 
Equipment. 

514.1 Operating Procedures. 

514.1.1 Exhaust systems shall be operated 
whenever cooking equipment is turned on. 

514.1.2 Filter-equipped exhaust systems shall 
not be operated with filters removed. 

514.1.3 Openings provided for replacing air 
exhausted through ventilating equipment shall 
not be restricted by covers, dampers, or any 
other means that would reduce the operating 
efficiency of the exhaust system. 

514.1.4 Instructions for manually operating the 
fire-extinguishing system shall be posted 
conspicuously in the kitchen and shall be 
reviewed periodically with employees by the 
management. 

514.1.5 Listed exhaust hoods shall be operated 
in accordance with the terms of their listings and 
the manufacturer's instiuctioiis. 



514.1.6 Cooking eqtiipment shall not be operated 
while its fire-extinguishing system or exhaust 
system is nonoperational or otherwise impaired. 

514.1.7 Secondary filtration and pollution 
control equipment shall be operated in 
accordance with the terms of their listing and the 
manufacturer's recommendations. [NFPA 96: 
11.1.7] 

514.1.8 Inspection and maintenance of 
equipment allowed in Section 512.3.1 shall be 
conducted by properly trained and qualified 
per-sons at a frequency determined by the 
manufacturer's instructions or equipment listing. 
[NFPA 96: 11.1.8] 

514.2 Inspection. Maintenance of the fire- 
extinguishing system and listed exhaust hoods 
containing a constant or fire-actuated water system 
that is listed to extinguish a fire in the grease 
removal devices, hood exhaust plenums, and 
exhaust ducts shall be made by properly trained, 
qualified, and certified person(s) or company 
acceptable to the Authority Having Jurisdiction at 
least every sue (6) months. [NFPA 96 11.2.1] 

514.2.1 All actuation components, including 
remote manual pull stations, mechanical or 
electrical devices, detectors, actuators, and fire- 
actuated dampers, shall be checked for proper 
operation during the inspection in accordance 
with the manufacturer's listed procedures. In 
addition to these requirements, the specific 
inspection requirements of the applicable NFPA 
standard shall also be followed. [NFPA 96:11.2.2 
&11.2.3] 

514.2.2 Fusible links (including fusible links on 
fire damper assemblies) and automatic sprinkler 
heads shall be replaced at least semiannually, or 
more frequently if necessary where required by 
the manufachirer. [NFPA 96: 11.2.4] 

514.2.3 If required, certificates of inspection and 
maintenance shaU be provided. 

514.3 Cleaning. 

514.3.1 Hoods, grease removal devices, fans, 
ducts, and other appurtenances shall be cleaned 
to bare metal or the original factory coating at | 
frequent intervals prior to surfaces becoming 
heavily contaminated with grease or oily 
sludge. After the exhaust system is cleaned, it - 
shall not be coated with powder or other 
substance. The entire exhaust system shall be 
inspected by a properly trained, qualified, and 
certified company or person(s) in accordance - 
with Table 5-4. 



84 



EXHAUST SYSTEMS 



Table 5-4 -51 5.3 



TABLE 5-4 
Exhaust System Inspection Schedule 



Type or Volume of Cooking 
Frequency 


Frequency 


Systems serving solid-fuel cooking operations 


Monthly 


Systems serving high-volume cooking 
operations such as 24-hour cooking, 
charbroiling, or Virok cooking 


Quarterly 


Systems serving moderate- 
volume cooking operations 


Semiannually 


Systems serving low-volume cooking 
operations, such as churches, day camps, 
seasonal businesses, or seruor centers 


Annually 



514.3.1.1 Upon inspection, if found to be 
contaminated with deposits from grease- 
laden vapors, the contaminated portions of 
the exhaust system shall be cleaned by a 
properly trained, qualified, and certified 
company or person(s) acceptable to the 
Authority Having Jurisdiction in accordance 
with Section 514.3. [NFPA 96: 11.4.1] 

514.3.1.2 When a vent-cleaning service is 
used, a certificate showing date of inspection 
or cleaning shall be maintained on the 
premises. After cleaning is completed, the 
vent-cleaning contractor shall place or 
display within the kitchen area a label 
indicating the date cleaned and the name of 
the servicing company. It shall also indicate 
areas not cleaned. 

514.3.2 Flammable solvents or other flammable 
cleaning aids shall not be used. 

514.3.3 At the start of the cleaning process, 
electrical switches that could be activated 
accidentally shall be locked out. 

514.3.4 Components of the fire suppression 
system shall not be rendered inoperable during 
the cleaning process. 

Exception: Servicing by properly trained 
and qualified persons in accordance with 
, Section 514.2. 

51 4.3.5 Care shall be taken not to apply cleaning 
chemicals on fusible links or other detection 
devices of the automatic extinguishing system. 

514.3.6 When cleaning procedures are completed, 
all electrical switches and system components 
shall be returned to an operable state. All access 
panels (doors) and cover plates shall be 
replaced. Dampers and diffusers shall be 
positioned for proper airflow. 



514.4 Operation, Maintenance, and Inspection of 
Solid-Fuel Cooking Equipment. 

Where solid-fuel cooking equipment is used, the 
special provisions of Section 517.0 shall apply. 

515.0 Minimum Safety Requirements for Cooking 
Equipment. 

515.1 Cooking Equipment. 

515.1.1 Cooking equipment shall be approved 
based on one of the following criteria: 

(A) Listings by a testing laboratory. 

(B) Test data acceptable to the Authority 
Having Jurisdiction. 

515.1.2 Installation. 

515.1.2.1 All listed appliances shall be 
installed in accordance with the terms of 
their listings and the manufacturer's 
instructions. 

515.1.2.2 Cooking appliances requiring 
protection shall not be moved, modified, or 
rearranged without prior reevaluation of the 
fire-extinguishing system by the system 
installer or servicing agent, tinless otherwise 
allowed by the design of the fire- 
extinguishing system. 

Exception: Cooking appliances moved 
to perform maintenance and cleaning, 
provided the appliances are returned to 
their original positioning prior to 
cooking operations, and any dis- 
connected fire-extinguishing system 
nozzles attached to the appliances are 
reconnected in accordance with the 
manufacturer's listed design manual. 

515.1.2.3 All deep-fat fryers shall be 
installed with at least a sixteen (16) inch 
(406.4 mm) space between the fryer and 
surface flames from adjacent cooking 
equipment. . 

Exception: Where a steel or tempered 
glass baffleplate is installed at a 
minimum eight (8) inches (203 mm) in 
height between the fryer and surface 
flames of the adjacent appliance. 

515.2 Operating Controls. Deep-fat fryers shall be 
equipped with a separate high-limit control in 
addition to the adjustable operating control 
(thermostat) to shut off fuel or energy when the fat 
temperature reaches 475°F (246°C) at one (1) inch 
(25.4 mm) below the surface. 

515.3 Cooking Equiprhent Maintenance. [NFPA 
96: 11.5] 



85 



515.3-516.3 



2007 CALIFORNIA MECHANICAL CODE 



515.3.1 An inspection and servicing of the 
cooking equipment shall be made at least 
annually by properly trained and qualified 
persons. [NFPA 96: 11.5.1] 

51 5.3.2 Cooking equipment that collects grease 
below the surface, behind the equipment, or in 
cooking equipment flue gas exhaust, such as 
griddles or charbroilers, shall be inspected and, 
if found with grease accumulation, cleaned by a 
properly trained, qualified, and certified person 
acceptable to the authority having jurisdiction. 
[NFPA 96: 11.5.2] 

516.0 Recirculating Systems. 

516.1 General Requirements. Recirculating 
systems containing or for use with appliances used 
in processes producing smoke or grease-laden 
vapors shall be equipped with components 
complying with the following: 

(A) The clearance requirements of Section 507.2. 

(B) A hood complying with the requirements of 
Section 508.0. 

(C) Grease removal devices compl5dng with 
Section 509.0. 

(D) The air movement requirements of Sections 
511.2.1 and 511.2.2. 

(E) Auxiliary equipment (such as particulate 
and odor removal devices) complying with 
Section 512.0. 

(F) Fire-extinguishing equipment complying 
with the reqiiirements of Section 513.0. 

Exception: References to ducts in 
Sections 513.1.1 and 513.5.1. 

(G) The use and maintenance reqtiirements of 
514.0. 

(H) The minimum safety requirements of 
Section 515.0. 

(I) All the requirements of this chapter. 

516.2 Design Restrictions. All recirculating 
systems shall comply with Section 516.2. 

51 6.2.1 Only gas- or electrically fueled cooking 
appliances shall be used. Gas-fueled appliances 
shall not have the combustion flue outlet(s) directly 
connected to the recirculating system. Gas-fueled 
appliances shall have a minimtim eighteen (18) 
inch (457.2 mm) clearance from the flue outlet to 
the filter inlet in accordance with Section 509.2.2 
and shall meet the installation requirements of 
NFPA 54, National Fuel Gas Code, or NFPA 58, 
Liquefied Petroleum Gas Code. 

516.2.2 Recirculating systems shall be listed 
with a testing laboratory. There shall be no 



substitution or exchange of cooking appliances, 
filter components, blower components, or fire- 
extinguishing system components that would 
violate the listing of the appliance. 

51 6.2.3 A recirculating system shall not use 
cooking equipment that exceeds that 
recirculating system's labeled maximum limits 
for that type of equipment, stated in maximum 
energy input, maximum cooking temperature, 
and maximum square area of cooking surface or 
cubic volume of cooking cavity. [NFPA 
96:13.2.6] 

516.2.4 A fire-actuated damper shall be installed 
at the exhaust outlet of the system. The damper 
shall be constructed of at least the same gauge as 
the shell. The actuation device shall have a 
maximtun temperature rating of 375°F (190°C). 

51 6.2.5 No electrical wiring shall be installed 
in the interior sections of the hood plenum that 
might become exposed to grease. 

Exception: As permitted by California 
Electrical Code. 

516.2.6 The power supply of any electrostatic 
precipitator (ESP) shall be of the "cold spark," 
ferro-resonant type in that the voltage falls off as 
the current draw of a short increases. 

516.2.7 Listing evaluation shall include the 
following: 

(A) Capture and contairmient of vapors at 
published and labeled airflows. 

(B) Grease discharge at the exhaust outlet 
of the system not to exceed an average 
of 5 mg/m^ of exhausted air sampled 
from that equipment at maximum 
amount of product that is capable of 
being processed over a continuous eight 
(8) hour test per EPA Test Method 202, 
Determination of Condensable Par- 
ticulate Emissions for Stationary 
Sources, with the system operating at its 
minimum listed airflow. 

(C) Listing and labeling of clearance to 
combustibles from all sides, top, and 
bottom. 

(D) Electrical connection in the field in 
accordance with California Electrical Code. 

(E) Interlocks on aU removable components 
that lie in the path of airflow within the 
unit to ensure ihat they are in place during 
operation of the cooking appliance. 

516.3 Interlocks. The recirculating system shall be 
provided with interlocks of all critical components 
and operations as indicated in Sections 516.3.1 
through 516.3.4 such that, if any of these interlocks 



86 



EXHAUST SYSTEMS 



516.3-517.2 



are interrupted, the cooking appliance shall not be 
able to operate. 

516.3.1 All closure panels encompassing 
airflow sections shall have interlocks to ensure 
the panels are in place and fully sealed. 

51 6.3.2 Each filter component (grease and odor) 
shall have an interlock to prove the component 
is in place. 

51 6.3.3 Each ESP shall have a sensor to prove its 
performance is as designed, with no interruption 
of the power to exceed two (2) minutes. This 
sensor shall be a manual reset device or circuit. 

516.3.4 An airflow switch or transducer shall be 
provided after the last filter component to 
ensure that a minimum airflow is maintained. 
This device opens the interlock circuit when the 
airflow falls 25 percent below the system's 
normal operating flow or 10 percent below its 
listed minimum rating, whichever is lower. This 
switch or transducer shall be a manual reset 
device or circuit. 

516.4 Location and Application Restrictions. The 

location of recirculating systems shall be approved by 
the Authority Having Jurisdiction. Items to be reviewed 
in the fire risk assessment shall include, but not be 
limited to, life safety, combustibility of surrotmdings, 
proximify to air vents, and total fuel load. 

516.5 Additional Fire Safety Requirements. 

516.5.1 In addition to the appliance nozzle(s), a 
recirculating system shall be listed with the 
appropriate fire protection for grease filters, 
grease filtration, odor filtration units, and 
ductwork where applicable. 

516.5.2 In addition to any other fibre-extinguishing 
system actuation device, there shall be a fire- 
extinguishing system actuation device installed 
downstream of any ESP. 

51 6.5.3 The requirements of Section 513.6 shall 
also apply to recirculating system locations. 

516.6 Use and Maintenance. 

516.6.1 Automatic or manual covers on cooking 
appliances, especially fryers, shall not interfere 
with the application of the fire suppression system. 

51 6.6.2 All filters shall be cleaned or replaced in 
accordance with the manufacturer's instructions. 

516.6.3 All ESPs shall be cleaned a minimum of 
once per week following manufacturer's 
cleaning instructions. 

51 6.6.4 The entire hood plenum and the blower 
section shall be cleaned a minimum of once 

' every three (3) months. 

516.6.5 Inspection and testing of the total 
operation and all safety uiterlocks in accordan.ce 



with the manufacturer's instructions shall be 
performed by qualified service personnel a 
minimum of once every six (6) months, or more 
frequently if required. 

Exception: Fire-extinguishing equipment 
shall be inspected in accordance with 
Section 514.2. 

51 6.6.6 A signed and dated log of maintenance 
as performed in accordance with Sections 516.6.4 
and 516.6.5 shall be available on the premises for 
use by the Authority Having Jurisdiction. 

517.0 Solid-Fuel Cool<ing Operations. 

517.1 Venting Application. Venting requirements 
of solid-fuel cooking operations shall be determined 
in accordance with Sections 517.1.1 through 517.1.6. 

517.1.1 Where solid-fuel cooking equipment is 
required by the manufacturer to have a natural 
draft, the vent shall comply with Section 517.4. 

517.1 .2 Where the solid-fuel cooking equipment 
has a self-contained top, is the only appliance to 
be vented in an isolated space (except for a single 
water heater with its own separate vent), has a 
separate makeup-air system, and is provided 
with supply and return air (not supplied or 
returned from other spaces), the system shall 
comply with Sections 517.4 and 517.6. - 

517.1.3 Where the solid-fuel cooking equipm.ent 
is located in a space with other vented 
equipment, all vented equipment shall have an 
exhaust system interlocked with a makeup-air 
system for the space as per Section 517.6. 

517.1.4 Natural draft ventilation systems and 
power-exhausted ventilation systems shall 
comply with Sections 517.3, 517.4, and 517.6. 

517.1.5 Where a solid-fuel cooking appliance 
allows effluent to escape from the appliance 
opening, this opening shall be covered by a hood 
and an exhaust system that meets the 
requirements of Sections 517.3, 517.4, and 517.6. 

517.1.6 Solid-fuel cooking operations shall have 
spark arresters to minimize the passage of 
airborne sparks and embers into plenums and 
ducts. Where the solid-fuel cooking operation is 
not located under a hood, a spark arrester shall 
be provided to minimize the passage of sparks 
and embers into flues and chimneys. 

517.2 Location of Appliances. 

517.2.1 Every appliance shall be located with 
respect to building construction and other 
eqtdpment so as to permit access to the appliance. 



87 



517.2-517.7 



2007 CALIFORNIA MECHANICAL CODE 



517.2.2 Solid-fuel cooking appliances shall not 
be installed in confined spaces. The space or 
room shall be of ample size to permit adequate 
circulation of heated air. 

Exception: Solid-fuel cooking appliances 
listed for installation in confined spaces 
such as alcoves shall be installed in 
accordance with the terms of the listing and 
the manufacturer's instructions. 

517.2.3 Solid-fuel cooking appliances shall not 
be installed in any location where gasoline or 
any other flammable vapors or gases are likely 
to be present. 

517.3 Hoods for Solid-Fuel Cooking. 

517.3.1 Hoods shall be sized and located in a 
manner capable of capturing and containing all 
of the effluent discharging from the appliances. 
The hood and its exhaust system shall comply 
with the provisions of the code. 

517.3.2 All solid-fuel cooking equipment 
served by hood and duct systems shall be 
separate from all other exhaust systems. 

Exception: Cooking equipment not requiring 
automatic fire-extinguishing equipment (as 
per the provisions of Section 510.0) shall be 
permitted to be installed under a common 
hood with solid-fuel cooking equipment that 
is served by a duct system separate from all 
other exhaust systems. 

517.4 Exhaust Systems for Solid-Fuel Cooking. 

Where a hood is not required, in buildings where the 
duct system is three stories or less in height, a duct 
complying with Section 510.0 shall be provided. 

517.4.1 If a hood is used, the duct system shall 
conform with the Section 510.0. 

517.4.2 A listed or approved grease duct system 
shall be provided for solid-fuel cooking exhaust 
systems that are four stories in height or greater. 

517.4.3 Where a hood is used, the duct system 
shall conform with the requirements of Section 
510.0. 

517.4.4 Wall terminations of solid-fuel exhaust 
systems shall be prohibited. 

517.5 Grease Removal Devices for Solid-Fuel 
Cooking. Grease removal devices shall be 
constructed of steel or stainless steel or be approved 
for solid-fuel cooking. 

517.5.1 If airborne sparks and embers can be 
generated by the solid-fuel cooking operation, 
spark arrester devices shall be used prior to the 
grease removal device to minimize the entrance of 



these sparks and embers into the grease removal 
device and into the hood and duct system. 

517.5.2 Filters shall be a minimum of four (4) 
feet (1.2 m) above the appliance cooking surface. 

517.6 Air Movement for Solid-Fuel Cooking. 

Exhaust system requirements shall comply with the 
provisions of the code for hooded operation or shall 
be installed in accordance with the manufacturer's 
recommendation for unhooded applications. 

517.6.1 A replacement or makeup-air system 
shall be provided to ensure a positive supply of 
replacement air at all times during cooking 
operations. 

517.6.2 Makeup-air systems serving solid-fuel 
cooking operations shall be interlocked with the 
exhaust-air system and powered, if necessary, to 
prevent the space from attaining a negative pressure 
while the solid-fuel appliance is in operation. 

517.7 Fire-Extinguishing Equipment for Solid- 
Fuel Cooking. 

51 7.7.1 Approved fire-extinguishing equipment 
shall be provided to protect all solid-fuel- 
burning cooking appliances that might be a 
source of ignition of grease in the hood, grease 
removal device, or duct. 

Exception: If acceptable to the Authority 
Having Jurisdiction, solid-fuel-burning 
cooking appliances constructed of solid 
masonry or reinforced portland or refractory 
cement concrete and vented in accordance 
with NFPA 211, Standard for Chimneys, 
Fireplaces, Vents, and Solid Fuel-Burning 
Appliances, Chapters 3 and 4, shall not require 
fixed automatic fire-extinguishing equipment. 

517.7.2 Approved fire-extinguishing equipment 
shall be provided for the protection of grease 
removal devices, hoods, and duct systems. 

Exception: If acceptable to the Authority 
Having Jurisdiction, solid-fuel-burning 
cooking appliances constructed of solid 
masonry or reinforced portland or refractory 
cement concrete and vented in accordance 
with NFPA 211, Standard for Chimneys, 
Fireplaces, Vents, and Solid Fuel-Burning 
Appliances, Chapters 3 and 4, shall not require 
automatic fire-extinguishing equipment. 

51 7.7.3 Approved fire-extinguishing equipment 
for solid-fuel-burriing cooking appliances, where 
required, shall comply with NFPA 211 and shall 
be comprised of water-based agents. 

517.7.4 Fire-extinguishing equipment shall be 
rated and designed to extingtush solid-fuel cooking 
fires, in accordance with the manufacturer's 



88 



EXHAUST SYSTEMS 



517.7-517.8 



recommendations. The fire-extinguishing 
equipment shall be of sufficient size to totally 
extinguish fire in the entire hazard area and 
prevent reigrution of the fuel. 

51 7.7.5 All solid-fuel appliances (whether or not 
under a hood) with fireboxes of 5 ft.^ (0.14 m?) 
volume or less shall at least have a listed 2-A- 
rated water-type fire extinguisher or a 1.6 gal (6 
L) wet chemical fire extinguisher listed for Class 
K fires in accordance with NFPA 10, in the 
immediate vicinity of the appliance. [NFPA 
96:14.7.8] 

517.7.6 Solid-fuel appliances with fireboxes 
exceeding 5 ft.^ (0.14 m') shall be provided with a 
fixed-water-pipe system with a hose in the 
immediate vicinity of the appliance. [NFPA 
96:14.7.9.1] The hose shall be equipped with an 
adjustable nozzle capable of producing a fine to 
medium spray or mist. [NFPA 96 14.7.9.1.1] The 
nozzle shall be of the type that cannot produce a 
straight stream. [NFPA 96 14.7.9.1.2] The system 
shall have a minbraim operating pressure of 40 psi 
(275.8 kPa) and shall provide a minimum of 5 gpm. 
[NFPA 96:14.7.9.2] 

51 7.7.7 Fire suppression for fuel storage areas 
shall comply with Section 517.9. 

517.7.8 In addition to the requirements of 
Sections 517.7.5 or 517.7.6, where any solid-fuel 
cooking appliance is also provided with 
auxiliary electric, gas, oil, or other fuel for 
ignition or supplemental heat and the appliance 
is also served by any portion of a fire- 
extinguishing system complying with Section 
513.0, such auxiliary fuel shall be shut off upon 
actuation of the fire-extingtdshing system. 

517.8 Other Safety Requirements. 

517.8.1 Metal-fabricated solid-fuel cooking 
appliances shall be listed for the application 
where produced in practical quantities or shall be 
approved by the Authority Having Jurisdiction. 
When listed, they shall be installed in accordance 
with the terms of their listings and with the 
applicable requirements of this standard. 

517.8.2 Site-built solid-fuel cooking appliances 
shall be submitted for approval to the Authority 
Having Jurisdiction before being considered for 
installation. All units shall be installed, operated, 
and maintained in accordance with the 
approved terms of the manufacturer's instruc- 
tions and any additional requirements set forth 
by the Authority Having Jurisdiction. 

517.8.3 Except for the spark arrester required in 
Section 517.1.6, there shall be no additional 



devices of any type in any portion of the 
appliance, flue pipe, and chimney of a natural 
draft solid-fuel operation. 

517.8.4 No solid-fuel cooking device of any 
type shall be permitted for deep-fat frying 
involving more than one (1) quart of liquid 
shortening, nor shall any solid-fuel cooking 
device be permitted within three (3) feet (0.92 m) 
of any deep-fat frying unit. 



89 



Table 5-5 



2007 CALIFORNIA MECHANICAL CODE 



TABLE 5-5 
Minimum Sheet IVIetal Tliicl^ness for Round Ducts for Product-Conveying System Ducts 



Negative 
Pressure 


Reinf. 
Spacing 
(Inches) 


Class 1 


Up to 7" 


8" to 11" 


12" to 15" 


16" to 19" 


20" to 23" 


24" to 35" 


36" to 47" 


48" to 59" 


60" 


To 7" 



96 
48 
24 


.02l(24ga.) 
.021(24ga.) 
.021(24ga.) 
.021(24ga.) 


.021(24ga.) 
.021(24ga.) 
.021(24ga.) 
.021(24ea.) 


.033(20ga.) 
.021(24ga.) 
.021 (24 ga.) 
.021 {24 ga.) 


.044(18ga.) 
.027(22ga.) 
.021(24ga.) 
.021{24ga.) 


.055(16ga.) 
.033(20sa.) 
.021(24ga.) 
.021(24ga.) 


.068(14ga.) 
.044(18ga.) 
.027(22ga.) 
.021(24ea.) 


.127(10ga.) 
.055(16ga.) 
.033(20ga.) 
.027 (22 ea.) 


.068(14ga.) 
.044(18ga.) 
.033 (20 ga.) 


.068(14ga.) 
.055(16ga.) 
.044(18ga.) 


8" to 11" 



96 
48 
24 


.021(24ga.) 
.021(24ga.) 
.021(24ga.) 
.021(24Ka.) 


.027(22ga.) 
.027(22ga.) 
.021(24ga.) 
.021(24ga.) 


.044 (18 ga.) 
.027(22ga.) 
.021(24ga.) 
.021(24ga.) 


.055(16ga.) 
.044 (18 ga.) 
.027(22ga.) 
.021(24Ka.) 


.068 (14 ga.) 
.044(18ga.) 
.033 (20 ga.) 
.027(22ga.) 


.097(12ga.) 
.044 (18 ga.) 
.033(20ga.) 
.027(22ga.) 


.068 (14 ga.) 
.055(16ga.) 
.044(18ga.) 


.097(12ga.) 
.068 (14 ga.) 
.055(16ga.) 


.097(12ga.) 
.068(14ga.) 
.055(16ga.) 


12" to 15" 



96 
48 
24 


.021(24ga.) 
.021(24ga.) 
.021(24ga.) 
.021(24ga.) 


.033 (20 ga.) 
.027(22ga.) 
.027(22ga.) 
.021(24ga.) 


.055(16ga.) 
.044(18ga.) 
.027(22ga.) 
.021(24ga.) 


.068(14ga.) 
.044(18ga.) 
.033(20ga.) 
.027(22ga.) 


.097(12ga.) 
.055(16ga.) 
.044(18ga.) 
.027(22ga.) 


.097(12ga.) 
.055(16ga.) 
.044(18ga.) 
.027(22ga.) 


.097(12ga.) 
.068(14ga.) 
.055 (16 ga.) 


.112(llga.) 
.068 (14 ga.) 
.055(16ga.) 


.112(llga.) 
.097(12ga.) 
.055(16ga.) 


16" to 20" 



96 
48 
24 


.021(24ga.) 
.021(24ga.) 
.021(24ga.) 
.021(24Ra.) 


.044(18ga.) 
.033(20ga.) 
.027(22ga.) 
.021(24ga.) 


.068(14ga.) 
.055 (16 ga.) 
.033 (20 ga.) 
.027(22ga.) 


.097(12ga.) 
.055(16ga.) 
.044(18ga.) 
.033 (20 ga.) 


.112(llga.) 
.068(14ga.) 
.055(16ga.) 
.044(18ga.) 


.068(14ga.) 
.055(16ga.) 
.044 (18 ga.) 


•112(llga.) 
.068(14ga.) 
.055(16ga.) 


.112(llga.) 
.097(12ga.) 
.068 (14 ga.) 


.112(llga.) 
.112(llga.) 
.097(12ga.) 


To 7" 



96 
48 
24 


Class 2 


.027(22ga.) 
.027(22ga.) 
.027(22ga.) 
.027(22ga.) 


.027(22ga.) 
.027(22ga.) 
.027(22ga.) 
.027(22ga.) 


.033 (20 ga.) 
.033(20ga.) 
.033(20ga.) 
.033 (20 ga.) 


.044 (18 ga.) 
.033 (20 ga.) 
.033 (20 ga.) 
.033 (20 ga.) 


.055 (16 ga.) 
.044(18ga.) 
.044 (18 ga.) 
.044(18ga.) 


.068 (14 ga.) 
.044 (18 ga.) 
.044 (18 ga.) 
.044(18ga.) 


.127(10ga.) 
.055 (16 ga.) 
.055(16ga.) 
.055(16ga.) 


.068 (14 ga.) 
.055(16ga.) 
.055(16ga.) 


.068(14ga.) 
.055(16ga.) 
.055(16ga.) 


8" to 11" 



96 
48 
24 


.027(22ga.) 
.027(22ga.) 
.027(22ga.) 
.027(22ga.) 


.027(22ga.) 
.027(22ga.) 
.027(22ga.) 
.027(22ga.) 


.044 (18 ga.) 
.033 (20 ga.) 
.033 (20 ga.) 
.033(20ga.) 


.055(16ga.) 
.044 (18 ga.) 
.033 (20 ga.) 
.033(20ga.) 


.068(14ga.) 
.044(18ga.) 
.044(18ga.) 
.044(18ga.) 


.097(12ga.) 
.044 (18 ga.) 
.044(18ga.) 
.044 (18 ga.) 


.068 (14 ga.) 
.055(16ga.) 
.055(16ga.) 


.097(12ga.) 
.068(14ga.) 
.055(16ga.) 


.097(12ga.) 
.068 (14 ga.) 
.055(16ga.) 


12" to 15" 



96 
48 
24 


.027(22ga.) 
.027(22ga.) 
.027(22ga.) 
.027(22ga.) 


.033(20ga.) 
.033(20ga.) 
.027(22ga.) 
.027(22ga.) 


.055(16ga.) 
.044 (18 ga.) 
.033(20ga.) 
.033(20ga.) 


.068 (14 ga.) 
.044(18ga.) 
.033 (20 ga.) 
.033 (20 ga.) 


.097(12ga.) 
.055(16ga.) 
.044(18ga.) 
.044(18ga.) 


.097(12ga.) 
.055(16ga.) 
.044 (18 ga.) 
.044(18ga.) 


.097(12ga.) 
.068 (14 ga.) 
.055(16ga.) 


.112(llga.) 
.068(14ga.) 
.055(16ga.) 


.112 (11 ga.) 
.097(12ga.) 
.055(16ga.) 


16" to 20" 



96 
48 
24 


.027(22ga.) 
.027(22ga.) 
.027(22ga.) 
.027(22ga.) 


.044(18ga.) 
.033 (20 ga.) 
.033 (20 ga.) 
.033(20ga.) 


.068(14ga.) 
.055 (16 ga.) 
.033 (20 ga.) 
.033(20ga.) 


•097(12ga.) 
.055 (16 ga.) 
.044 (18 ga.) 
.033 (20 ga.) 


■112(llga.) 
.068(14ga.) 
.055(16ga.) 
.044 (18 ga.) 


.068(14ga.) 
.055(16ga.) 
.044 (18 ga.) 


.112(llga.) 
.068 (14 ga.) 
.055(16ga.) 


.112(llga.) 
.068(14ga.) 
.055(16ga.) 


.112(llga.) 
.097(12ga.) 
.055(16ga.) 


To 7" 



96 

48 
24 


Class 3 


.033 (20 ga.) 
.033 (20 ga.) 
.033(20ga.) 
.033(20ga.) 


.033(20ga.) 
.033(20ga.) 
.033(20ga.) 
.033 (20 ga.) 


.044 (18 ga.) 
.044 (18 ga.) 
.044 (18 ga.) 
.044 (18 ga.) 


.044 (18 ga.) 
.044(18ga.) 
.044(18ga.) 
.044(18ga.) 


.055(16ga.) 
.055(16ga.) 
.055(16ga.) 
.055(16ga.) 


.068(14ga.) 
.055(16ga.) 
.055(16ga.) 
.055(16ga.) 


.127(10ga.) 
.068(14ga.) 
.068(14ga.) 
.068(14ga.) 


.068 (14 ga.) 
.068 (14 ga.) 
.068(14ga.) 


.068(14ga.) 
.068(14ga.) 
.068(14ga.) 


8" to 11" 



96 
48 
24 


.033 (20 ga.) 
.033 (20 ga.) 
.033 (20 ga.) 
.033(20ga.) 


.033(20ga.) 
.033 (20 ga.) 
.033 (20 ga.) 
.033(20ga.) 


.044 (18 ga.) 
.044 (18 ga.) 
.044 (18 ga.) 
.044 (18 ga.) 


.055(16ga.) 
.044 (18 ga.) 
.044(18ga.) 
.044 (18 ga.) 


.068(14ga.) 
.055 (16 ga.) 
.055 (16 ga.) 
.055(16ga.) 


.097(12ga:) 
.055 (16 ga.) 
.055(16ga.) 
.055(16ga.) 


.068 (14 ga.) 
.068 (14 ga.) 
.068 (14 ga.) 


.097(12ga.) 
.068(14ga.) 
.068(14sa.) 


.097(12ga.) 
.068 (14 ga.) 
.068 (14 ga.) 



90 



EXHAUST SYSTEMS 



Table 5-5 - Table 5-6 



TABLE 5-5 (Continued) 
Minimum Slieet IVIetal Thickness for Round Ducts for Product-Conveying System Ducts 



Negative 
Pressure 


Reinf. 
Spacing 
(Inches) , 


Class 3 


Up to 7" 


8" to 11" 


12" to 15" 


16" to 19" 


20" to 23" 


24" to 35" 


36" to 47" 


48" to 59" 


60" 


12" to 15" 




96 
48 
24 


.033 (20 ga.) 
.033 (20 ga.) 
.033(20ga.) 
.033 (20 ga.) 


.033 (20 ga.) 
.033 (20 ga.) 
.033 (20 ga.) 
.033 (20 ga.) 


.055(16ga.) 
.044 (18 ga.) 
.044 (18 ga.) 
.044 (18 ga.) 


.068(14ga.) 
.044 (18 ga.) 
.044 (18 ga.) 
.044 (18 ga.) 


.097(12ga.) 
.055 (16 ga.) 
.055(16ga.) 
.055 (16 ga.) 


.097(12ga.) 
.055(16ga.) 
.055(16ga.) 
.055 (16 ga.) 


.097(12ga.) 
.068(14ga.) 
.068(14ga.) 


•112(llga.) 
.068 (14 ga.) 
.068(14 ga.) 


.112 (11 ga.) 
.068 (14 ga.) 
.068(14ga.) 


16" to 20" 




96 
48 
24 


.033(20ga.) 
.033(20ga.) 
.033(20ga.) 
.033(20ga.) 


.044 (18 ga.) 
.033 (20 ga.) 
.033 (20 ga.) 
.033(20ga.) 


.068 (14 ga.) 
.055(16ga.) 
.044(18ga.) 
.044 (18 ga.) 


.097(12ga.) 
.055(16ga.) 
.044 (18 ga.) 
.044 (18 ga.) 


.112(llga.) 
.068 (14 ga.) 
.055(16ga.) 
.055(16ga.) 


.068 (14 ga.) 
.055(16ga.) 
.055(16ga.) 


.112(llga.) 
.068(14ga.) 
.068(14ga.) 


•112(llga.) 
.068 (14 ga.) 
.068(14ga.) 


.112 (11 ga.) 
.097(12ga.) 
.068 (14 ga.) 


To 7" 




96 
48 
24 


Class 4 1 


.055(16ga.) 
.055 (16 ga.) 
.055(16ga.) 
.055(16ga.) 


.055(16ga.) 
.055(16ga.) 
.055(16ga.) 
.055(16ga.) 


.055(16ga.) 
.055 (16 ga.) 
.055 (16 ga.) 
.055(16ga.) 


.055(16ga.) 
.055(16ga.) 
.055(16ga.) 
.055(16ga.) 


.068(14ga.) 
.068(14ga.) 
.068 (14 ga.) 
.068(14ga.) 


.068(14ga.) 
.068(14ga.) 
.068(14ga.) 
.068(14ga.) 


.127(10ga.) 
.097(12ga.) 
.097(12ga.) 
.097(12ga.) 


.097(12ga.) 
.097(12ga.) 
.097(12ga.) 


.097(12ga.) 
.097(12ga.) 
.097(12ga.) 


8" to 11" 




96 
48 
24 


.055(16ga.) 
.055 (16 ga.) 
.055(16ga.) 
.055(16ga.) 


.055(16ga.) 
.055(16ga.) 
.055(16ga.) 
.055(16ga.) 


.055(16ga.) 
.055 (16 ga.) 
.055(16ga.) 
.055(16ga.) 


.055(16ga.) 
.055 (16 ga.) 
.055(16ga.) 
.055(16ga.) 


.068(14ga.) 
.068(14ga.) 
.068(14ga.) 
.068(14ga.) 


.097(12ga.) 
.068(14ga.) 
.068(14ga.) 
.068(14ga.) 


.097(12ga.) 
.097(12ga.) 
.097(12ga.) 


.097(12ga.) 
.097(12ga.) 
•097(12ga.) 


.097(12ga.) 
.097(12ga.) 
.097(12ga.) 


12" to 15" 




96 
48 
24 


.055(16ga.) 
.055(16ga.) 
.055(16ga.) 
.055(16ga.) 


.055(16ga.) 
.055 (16 ga.) 
.055 (16 ga.) 
.055(16ga.) 


.055(16ga.) 
.055(16ga.) 
.055(16ga.) 
.055(16ga.) 


.068(14ga.) 
.055(16ga.) 
.055(16ga.) 
.055 (16 ga.) 


.097(12ga.) 
.068(14ga.) 
.068 (14 ga.) 
.068 (14 ga.) 


.097(12ga.) 
.068(14ga.) 
.068 (14 ga.) 
.068(14ga.) 


.097(12ga.) 
.097(12ga.) 
.097(12ga.) 


•112 (11 ga.) 
•097(12ga.) 
.097(12ga.) 


.112 (11 ga.) 
.097(12ga.) 
.097(12ga.) 


16" to 20" 




96 
48 
24 


.055(16ga.) 
.055(16ga.) 
.055(16ga.) 
.055(16ga.) 


.055(16ga.) 
.055(16ga.) 
.055(16ga.) 
.055 (16 ga.) 


.068(14ga.) 
.055(16ga.) 
.055 (16 ga.) 
.055(16ga.) 


.097(12ga.) 
.055(16ga.) 
.055(16ga.) 
.055(16ga.) 


.112 (11 ga.) 
.068(14ga.) 
:068(14ga.) 
.068 (14 ga.) 


.068(14ga.) 
.068(14ga.) 
.068 (14 ga.) 


.112 (11 ga.) 
.097(12ga.) 
.097(12ga.) 


.112(llga.) 
.097(12ga.) 
.097(12ga.) 


.112(llga.) 
.097(12ga.) 
0.097 (12 ga.) 



TABLE 5-6 
IVIinimum Shieet l\/letal Thicl<ness for Rectangular Ducts 



Negative 
Pressure 


Reinf. 
Spacing 


Longest Side of Duct 


Class 1 


Class 2 


Up to 12" 


13" to 24" 


25" to 36" 


37" to 48" 


49" to 60" 


Up to 12" 


13" to 24" 


25" to 36" 


37" to 48" 


49" to 60" 


To 7" 
To 7" 
To 7" 

8" to 11" 
8" to 11" 
8" to 11" 

12" to 15" 
12" to 15" 
12" to 15" 

16" to 20" 
16" to 20" 
16" to 20" 


48 
24 
12 

48 
24 
12 

48 
24 
12 

48 
24 
12 


.021(24ga.) 
.021(24ga.) 
.021(24ga.) 

.027(22ga.) 
.027(22ga.) 
.021(24ga.) 

.044 (18 ga.) 
.044(18ga.) 
.027(22ga.) 

.068(14ga.) 
.068(14ga.) 
.033(20ga.) 


.033 (20 ga.) 
.027(22ga.) 
.021(24ga.) 

.068(14ga.) 
.055(16ga.) 
.027(22ga.) 

.097(12ga.) 
.055(16ga.) 
.044(18ga.) 

.112(llga.) 
.068(14ga.) 
.068(14ga.) 


.055(16ga.) 
.033(20ga.) 
.021(24ga.) 

.097(12ga.) 
.055(16ga.) 
.027(22ga.) 

.097(12ga.) 
.044(18ga.) 

.112(llga.) 
.068(14ga.) 


.068(14ga.) 
.033(20ga.) 
.021(24ga.) 

.097(12ga.) 
.068(14ga.) 
.027(22ga.) 

.097(12ga.) 
.044(18ga.) 

.112(llga.) 
.068(14ga.) 


.033(20ga.) 
.021(24ga.) 

.06S(14ga.) 
.027(22ga.) 

.097(12ga.) 
.044(18ga.) 

.112(llga.) 
.068(14ga.) 


.033 (20 ga.) 
.033(20ga.) 
.033(20ga.) 

.033(20ga.) 
.033(20ga.) 
.033(20ga.) 

.044(18ga.) 
.044(18ga.) 
.033(20ga.) 

.068 (14 ga.) 
.068(14ga.) 
.033(20ga.) 


.044(18ga.) 
.044(18ga.) 
.044(18ga.) 

.068(14ga.) 

.055(16ga.) 

.044(18ga.) 

.044(18ga.) 
.044(18ga.) 
.044(18ga.) 

.112(llga.) 
.068(14ga.) 
.044(18ga.) 


.055 (16 ga.) 

: .055(16ga.) 

.055(16ga.) 

.097(12ga.) 
.055(16ga.) 
.055(16ga.) 

;097(12ga,) 
.055(16ga.) 

•n2(iiga.) 

.068(14ga.) 


.068 (14 ga.) 
.055(16ga.) 
.055(16ga.) 

.097(12ga.) 
.068(14ga.) 
.055(16ga.) 

.097(12ga.) 
.055(16ga.) 

•112(llga.) 
.068(14ga.) 


.055(16ga.) 
.055(16ga.) 

.068(14ga.) 
.055(16ga.) 

.097(12ga.) 
.055(16ga.) 

.112(llga.) 
.068(14ga.) 


To 7" 
To 7" 
To 7" • 

8" to 11" 
8" to 11" 
8" to 11" 

12" to 15" 
12" to 15" 
12" to 15" 

16" to 20" 
16" to 20" 
16" to 20" 


48 
24 
12 

48 
24 
12 

48 
24 
12 

48 
24 
12 


Class 3 


Class 4 1 


.044 (18 ga.) 
.044{18ga.) 
.044(18ga.) 

.044{18ga.) 
.044(18ga.) 
.044(18ga.) 

.044 (18 ga.) 
.044(18ga.) 
.044(18ga.) 

.068(14ga.) 
.068(14ga.) 
.044(18ga.) 


.055(16ga,) 
.055(16ga.) 
.055(16ga.) 

.068(14ga.) 
.055(16ga.) 
.055{16ga.) 

.097(12ga.) 
.055(16ga.) 
.055(16ga.) 

.112(llga.) 
.068(14ga.) 
.068(14ga.) 


.068(14ga.) 
.068(14ga.) 
.068(14ga.) 

.097(12ga.) 
.068(14ga.) 
.068(14ga.) 

.097(12ga.) 
.068{14ga.) 

.112(llga.) 
.068(14ga.) 


.068(14ga.) 
.068(14ga.) 
.068(14ga.) 

.097(12ga.) 
.068(14ga.) 
.068(14ga.) 

.097(12ga.) 
.068(14ga.) 

.112(llga.) 
.068(14ga.) 


.068(14ga.) 
.068(14ga.) 

.068(14ga.) 
.068(14ga.) 

.097(12ga.) 
.068(14ga.) 

.112(llga.) 
.068(14ga.) 


.055(16ga.) 
.055(16ga.) 
.055(16ga.) 

.055(16ga.) 
.055a6ga.) 
.055(16ga.) 

.055(16ga.) 
.055(16ga.) 
.055(16ga.) 

.055(16ga.) 
.055(16ga.) 
.055(16ga.) 


.068(14ga.) 
.068(14ga.) 
.068(14ga.) 

.068(14ga.) 
.068(14ga.) 
.068{14ga.) 

.097(12ga.) 
.068(14ga.) 
.068(14ga.) 

.112(llga.) 
.068(14ga.) 
.a68(14ga.) 


.097(12ga.) 
.097(12ga.) 
.097(12ga.) 

.097(12ga.) 
.097(12ga.) 
.097(12ga.) 

.097(12ga.) 
.097(12ga.) 

.112(llga.) 
.097(12ga.) 


.097(12ga.) 
.097(12ga.) 
.097(12ga.) 

.097(12ga.) 
.097(12ga.) 
.097(12ga.) 

.097(12ga.) 
.097(12ga.) 

•112(llga.) 
•097{12ga.) 


.097(12ga.) 
.097(12ga.) 

.097(12ga.) 
.097{12ga.) 

.097(12ga.) 
.097(12ga.) 

.112(llga.) 
.097(12ga.) 



91 



Table 5-7 -Table 5-8 



2007 CALIFORNIA MECHANICAL CODE 



TABLE 5-7 
Construction, Clearance, and Termination Requirements for Unlisted Single-Wall Metal Chimneys 



CHIMNEYS SERVING 


MINIMUM THICKNESS 


TERMINATION 


CLEARANCE 


WALL 


LINING 


ABOVE 
ROOF 

OPENING 


ABOVE ANY PART 
OF BUILDING WITHIN 


COMBUSTIBLE 
CONSTRUCTION 


NONCOMBUSTIBLE 
CONSTRUCTION 


10' 


25' 


50' 


Interior Inst 


Exterior Inst. 


Interior Inst 


Exterior Insl 


Building-heating and 
industrial-type low-heat 
appliances (1, 000° F 
operatlng-1,400°F 
temp, maximum)' 


0.127" 

(Mfs. Std. 

10 ga.) 


None 


3' 


2' 






18" 


6" 


Up to 18" diameter, 2" 
Over 18" diameter, 4" 


Medium-heat Industrial- 
trial-type appliances 
(2,000° F maximum)'' = 


0.127" 

(Mfrs. Std. 

10 ga.) 


Up to 18" 

dia. -2-1/2" 

Over 18" 

i-1/2" on 4-1/2" bed 


10' 




10' 




36" 


24" 


High-heat industrial- 
appliances 
(Over 2,000° F)'' 2 


0.127' 

(Mfrs. Std. 

10 ga.) 


4-1/2" laid 

on 4-1/2" 

bed 


20' 






20' 


See footnote 3 


Residential-type 
incinerator' 


0.127' (Mfrs. 
Std. lOga.) 


None 


3' 


2' 






Not permitted 


18" 


Not permitted 


4" 



1 . Lining shall extend from bottom to top of chimney. 

2. Lining shall extend from 24 Inches (61 mm) below connector to 24 feet (7,31 5 mm) above. 

3. Clearance shall be as specified by the design engineer and shall have sufficient clearance from buildings 
and structures to avoid overheating combustible materials [maximum 160°F (71 °C)]. 



inches x 25.4 = mm 
feet X 304.8 = mm 
("F - 32) X 5/9 = °C 





TABLE 5-8 






Vent Selection Chart 




Column 1 
Type B, Gas 


Column II 


Column III 


Column IV 


Round or Oval 


Type BW Gas 


TypeL 


Plastic Pipe 


All listed gas appliances 


1. Gas-burning wall 


1. Oil-burning appliances 


1. Condensing appli- 


with draft hoods such as: 


heaters listed for use 


listed for use with 


ances listed for use 




with Type BW vents 


Type L vents 


with a specific 


1. Central furnaces 






plastic pipe 


2. Floor furnaces 




2. Gas appliances as 


recommended 


3. Heating boilers 




shown in coltunn I 


and identified in the 


4. Ranges and ovens 






manufacturer's 


5. Recessed wall furnaces 






installation 
instructions 



(above wall section) 

6. Room and xmit heaters 

7. Water heaters 



92 



CHAPTER 6 

DUCT SYSTEMS 



601.0 Scope. 

601.1 Ducts and plenums that are portions of a 
heating, cooling, absorption or evaporative cooling, 
or product-conveying system shall comply with the 
requirements of this chapter. 

601.2 Sizing Requirements. Duct systems used with 
blower-type equipment that are portions of a heating, 
cooUng, absorption, evaporative cooling, or outdoor-air 
ventilation system shall be sized in accordance with 
Chapter 17, or by other approved methods. 

Exception: [HCD 1] Duct sizing calculations are not 
required for existing duct systems. 

602.0 IVIaterial. 

602.1 General. Supply air, return air, arid outside 
air for heating, cooling, or evaporative cooling 
systems shall be conducted through duct systems 
constructed of metal as set forth in Tables 6-1, 6-2, 6- 
3, 6-4, 6-7, 6-8, 6-9, and 6-10, or metal ducts 
complying with UMC Standard No. 6-2 or the 
referenced HVAC duct construction standard in 
Chapter 17. Rectangular ducts in excess of two (2) 
inches w.g. shall comply with UMC Standard No. 6-2 
or the referenced HVAC duct construction standard 
in Chapter 17. Ducts, plenums, and fittings may be 
constructed of concrete, clay, or ceramics when 
installed in the ground or in a concrete slab, 
provided the joints are tightly sealed. 

Corridors shall not be used to convey air to or JErom 
rooms if the corridor is required to be of fire-resistive 
construction per the California Building Code. 

Exception [For OSHPD 1, 2, 3 & 4]: See Section 
407.4.1.3. 

Not permitted for [OSHPD 1, 2,3& 4/ Concealed 
building spaces or independent construction within 
btiildings may be used as ducts or.plenums. 

When gypsum products are exposed in ducts or 
plenums, the air temperature shall be restricted to a 
irange from SOT (10°C) to 125^ (52°C), and moisture 
content shall be controlled so that the material is not 
adversely affected. For the purpose of this section, 
gypsum products shall not be exposed in ducts 
serving as supply from evaporative coolers, and in 
other air-handling systems regulated by this chapter 
when the temperature of the gypsum product will be 
below the dew point temperature. 

See Chapter 8 for limitations on combustion 



products venting systems extending into or through 
ducts or plenums. 

See Chapter 5 for limitatior\s on environmental air 
systems exhaust ducts extending into or through 
ducts or plenums. 

Exhaust ducts under positive pressure and 
venting systems shall not extend into or pass 
through ducts or plenums. For appliance vents and 
chimneys, see Chapter 8. 

602.2 Combustibles Within Ducts or Plenums. 

Materials exposed within ducts or plenums shall be 
noncombustible or shall have a flame spread index 
not greater than twenty-five (25) and a smoke 
developed index not greater than fifty (50), when 
tested, as a composite product in accordance with 
one of the following test methods; NFEA 255, 
Method of Test of Surface Burning Characteristics of 
Building Materials, ASTM E84, Surface Burning 
Characteristics of Building Materials, or UL 723, Test 
for Surface Burning Characteristics of Building 
Materials, except as indicated below. 

Exceptions: 

(1) Return-air and outside-air ducts, plenums, 
or concealed spaces that serve a dwelling 
unit shall be permitted to be of combustible 
construction. 

(2) Air filters meeting the requirements of 
Sections 312.0 and 503.3. 

(3) Water evaporation media in an evaporative 
cooler. 

(4) Charcoal filters when protected with an 
approved fire suppression system.- 

(5) Electrical wiring in plenums shall comply 
with NFPA 70, National Electrical Code. 
Electrical wires and cables and optical fiber 
cables shall be listed and labeled as suitable 
for use in plenums and shall have a flame 
spread distance not greater than five (5) feet 
(1,524 mm), an average optical density not 
greater than 0.15, and a peak optical density 
not greater than 0.5, when tested in accordance 
with NFPA 262, Flame Travel and Smoke of 
Wires and Cables- for Use in Air-Handling 
Spaces. 

(6) Nonmetallic fire sprinkler piping in plenums 
shall be listed and labeled as siiitable for use 
in plenums and shall have a flame spread 



93 



602.2 - 602.5 



2007 CALIFORNIA MECHANICAL CODE 



distance not greater than five (5) feet (1,524 
mm), an average optical density not greater 
than 0.15 and, a peak optical density not 
greater than 0.5, when tested in accordance 
with UL 1887, Fire Test of Plastic Sprinkler 
Pipe for Visible Flame and Smoke 
Characteristics. 

(7) Nonmetallic pneumatic tubing in plenums 
shall be listed and labeled as suitable for use 
in plenums and shall have a flame spread 
distance not greater than five (5) feet 
(1,524mm), an average optical density not 
greater than 0.15, and a peak optical density 
not greater than 0.5, when tested in accordance 
with UL 1820, Fire Test of Pneumatic Tubing 
for Flame and Smoke Characteristics. 

(8) Loudspeakers and recessed lighting fixtures, 
including their assemblies and accessories, 
in plenums shall be listed and labeled as 
suitable for use in plenums and shaU have a 
peak rate of heat release not greater than 100 
kilowatts, an average optical density not 
greater than 0.15, and a peak optical density 
not greater than 0.5, when tested in accordance 
with UL 2043, Fire Test for Heat and Visible 
Smoke Release for Discrete Products and 
their Accessories Installed in Air-Handling 
Spaces. 

(9) Smoke detectors. 

(10) Duct insulation, coverings, and linings and 
other supplementary materials complying 
with 605.0. 

(11) Materials in a Group H, Division 6, fabrication 
area including the areas above and below 
the fabrication area sharing a common air 
recirculation path with the fabrication area. 

602.3 Factory-Made Air Ducts. Factory-made air 
ducts shall be approved for the use intended or shall 
conform to the requirements of the referenced 
standard for air ducts in Chapter 17. Each portion of a 
factory-made air duct system shall be identified by the 
manufacturer with a label or other suitable 
identification indicating compliance with the 
referenced standard for air ducts in Chapter 17 and its 
class designation. These ducts shall be listed and shall 
be installed in accordance with the terms of their 
listing and the requirements of UMC Standard No. 6- 
5. Flexible air connectors are not permitted. 

602.3.1 Flexible Ducts. [For OSHPD 1, 2, 3 & 

4] In hospital building projects and all other health- 
care facilities, including clinics and correctional 
treatment centers, flexible ducts of not more than 10 



feet (3048 mm) in length may be used to connect 
supply, return or exhaust-air terminal devices to rigid 
duct systems. Where constant volume, variable volume 
or mixing boxes are utilized, flexible duct of not more 
than 10 feet (3048 mm), may be used on the inlet side 
for alignment. An internal impervious liner shall be 
provided to isolate insulation material from 
conditioned air. 

602.4 Joints and Seams of Ducts. Joints of duct 
systems shall be made substantially airtight by 
means of tapes, mastics, gasketing, or other means. 

Crimp joints for round ducts shall have a contact 
lap of at least 1-1/2 inch (38 mm) and shall be 
mechanically fastened by means of at least three (3) 
sheet-metal screws equally spaced around the joint, 
or an equivalent fastening method. 

Joints and seams for 0.016 inch (0.41 mm) (No. 
28 gauge) and 0.013 inch (0.33 mm) (No. 30 gauge) 
residential rectangular ducts shall be as specified in 
Table 6-1 for 0.019 inch (0.48 mm) (No. 26 gauge) 
material. 

Joints and seams for rectangular duct systems 
shall be as specified in Table 6-1. 

Joints and seams for flat oval ducts and roimd 
ducts in other than single-dwelling tinits shall be as 
specified in Table 6-8. 

Joints and seams and all reinforcements for 
factory-made air ducts and plenums shaU meet with 
the conditions of prior approval in accordance with 
the installation instructions that shall accompany the 
product. Closure systems for rigid air ducts and 
plenxuns shall be listed in accordance with UL 181A, 
Standard for Closure Systems for Use with Rigid Air 
Ducts and Air Connectors. Closure systems for | 
flexible air ducts shall be listed in accordance with 
UL 181B, Standard for Closure Systems for Use with 
Flexible Air Ducts and Air Cormectors. 

602.5 IVletal. Every duct, plenum, or fitting of metal 
shaU comply with Table 6-1 or 6-8. 

Exceptions: 

(1) Ducts, plenums, and fittings for systems 
serving single-dwelling units may comply 
with Table 6-9. 

(2) Duct systems complying with UMC Standard 
6-2 or the referenced HVAC duct coristruction 
standard in Chapter 17, with prior approval, 
or duct systems complying with UL 181, 
Standard for Factory-Made Air Ducts and 
Air Connectors. 

(3) Duct systems complying with the UMC 
Standard 6-2 or the referenced HVAC duct 



94 



DUCT SYSTEMS 



602.5 - 604.6 



construction standard in Chapter 17, 
with prior approval. 

602.6 Tin. Existing tin ducts may be used when 
cooling coils are added to a heating system, provided 
the first ten (10) feet (3,048 mm) of the duct or 
plenum measured from the cooling coil discharge 
are constructed of metal of the gauge thickness set 
forth in Tables 6-1, 6-8, or 6-9 of this chapter or are of 
approved material and construction. Tin ducts 
completely enclosed in inaccessible concealed areas 
need not be replaced. All accessible ducts shall be 
insulated to comply with Table 6-6 of this chapter. 
For the purpose of this subsection, ducts shall be 
considered accessible where the access space is thirty 
(30) inches (762 ram) or greater in height. 

602.7 Vibration Isolators. Vibration isolators 
installed between mecharucal equipment and metal 
ducts (or casings) shall be made of an approved 
material and shall not exceed ten (10) inches (254 
mm) in length. 

603.0 Quality of Material. 

Galvanized steel shall be of lock-forming quality with a 
minimum coating of 1.25 oimces of zinc per square foot 
(0.04 kg/m^) conforming to the requirements of UMC 
Standard No. 2-2. 



604.0 installation of Ducts. 

604.1 General. Air ducts installed imder a floor in a 
crawl space shall be installed so as to maintain a 
vertical clearance of eighteen (18) inches for all 
portions of the duct that would obstruct access to 
any part of the crawl space. 

604.2 Metal Ducts. Ducts shall be securely fastened 
in place at each change of direction and as set forth 
in Table 6-7. Vertical rectangular ducts and vertical 
round ducts shall be supported as set forth in Table 
6-7, Part A. Riser ducts shall be held in place by 
means of metal straps or angles and channels to 
secure the riser to the structure. 

Metal ducts shall be installed with at least four (4) 
inches (102 mm) separation from earth. Metal ducts 
when installed in or under a concrete slab shall be 
encased in at least two (2) inches (51 mm) of concrete. 

Ducts shall be installed in a building with 
adequate clearance so as to permit retaining the full 
thickness of fireproofing on structural members. 

Supports for rectangular ducts as set forth in 
Table 6-7, when suspended from above, shall be 
installed on two opposite sides of each duct and shaU 



be riveted, bolted, or metal screwed to each side of 
the duct at not more than the intervals specified. 

Horizontal roimd ducts forty (40) inches (1,016 
mm) or less in diameter when suspended from above 
shall be supported at intervals not more than as set 
forth in Table 6-7 with one hanger installed to comply 
with the requirements listed below: 

604.2.1 Ducts shall be equipped with tight- 
fitting circular bands extending around the 
entire perimeter of the duct at each specified 
support interval. 

604.2.2 Circular bands shall be not less than one 
(1) inch (25.4 mm) wide nor less than equivalent 
to the gauge of the duct material it supports. 

Exception: Ducts ten (10) inches (254 mm) 
and less in diameter may be supported by 
No. 18 gauge galvanized steel wire. 

604.2.3 Each circular band shall be provided 
with a suitable means of connecting to the 
suspending support. 

604.2.4 Ducts shall be braced and guyed to 
prevent lateral or horizontal swing. 

604.3 Factory-Made Air Ducts. Listed Class or 
Class 1 factory-made air ducts may be installed in 
any occupancy covered by this code. 

Factory-made air ducts shall not be used for 
vertical risers in air-duct systems serving more than 
two stories. Such ducts shall not penetrate construction 
where fire dampers are required. 

Factory-made air ducts shall be installed with at 
least four (4) inches (102 mm) of separation from 
earth, except when installed as a liner inside of 
concrete, tile, or metal pipe; they shall be protected 
from physical damage. 

The temperature of the air to be conveyed in any 
of these classes of ducts shall not exceed 250°F (122°C). 

604.4 Protection of Ducts. Ducts installed in 
locations where they are exposed to mechanical 
damage by vehicles or from other causes shall be 
protected by approved barriers. 

604.5 Support of Ducts. Installers shall provide the | 
manufacturer's field fabrication and installation 
instructions. ^ 

In the absence of specific supporting materials 
and spacing, approved factory-made air ducts may 
be installed as set forth in Table 6-10. 

604.6 Protection Against Flood Damage. In flood 
hazard areas, ducts shall be located above the design 
flood elevation or shall be designed and constructed 
to prevent water from entering or accumulating 
within the ducts during floods up to the design flood 



95 



604.6 - 606.2 



2007 CALIFORNIA MECHANICAL CODE 



elevation. If the ducts are located below the design 
flood elevation, the ducts shall be capable of resisting 
hydrostatic and hydrodynamic loads and stresses, 
including the effects of buoyancy, during the 
occurrence of flooding to the design flood elevation. 

605.0 Insulation of Ducts. 

Supply- and return-air ducts and plenums of a 
heating or cooling system shall be insulated to 
achieve the minimum thermal (R) value as set forth 
in Tables 6-6 A and B. [OSHPD 1, 2, 3 & 4] Cold air 
ducts shall be insulated wherever necessary or to prevent 
condensation problems. 

Exceptions: 

(A) Factory-installed plenums, casings, or 
ductwork furnished as a part of HVAC 
equipment tested and rated in accordance 
with approved energy efficiency standards. 

(B) Ducts or plenums located in conditioned 
spaces. 

(C) For runouts less than ten (10) feet (3 m) in 
length to air terminals or air outlets, the rated R 
value of insulation need not exceed R-3.5 (R-0.6). 

(D) Backs of air outlets and outlet plenums 
exposed to unconditioned or indirectly 
conditioned spaces with face areas exceeding 
five (5) square feet (0.5 m^) need not exceed R- 
2 (R-0.4); those five (5) square feet (0.5 m^) or 
smaller need not be insulated. 

(E) Ducts and plenums used exclusively for 
evaporative cooling systems. 

Approved materials shall be installed within ducts 
and plenums for instilating, sound deadening, or other 
ptirposes. Materials shall have a mold, humidity, and 
erosion-resistant surface that meets the requirements 
of the referenced standard for air ducts in Chapter 17. 
Duct liners in systems operating with air velocities 
exceeding 2000 feet per minute (10.16 m/s) shaU be 
fastened with both adhesive and mechanical fasteners, 
and exposed edges shaU have adequate tieatment to 
withstand the operating velocity. 

Insulation applied to the surface of ducts, 
including duct coverings, linings, tapes, and 
adhesives, located in buildings shall have a flame- 
spread index not greater than twenty-five (25) and a 
smoke developed index not greater than fifty (50), 
when tested in accordance with NFFA 255, Method 
of Test of Burning Characteristics of Building 
Materials, or in accordance with ASTM E 84, Surface 
Burning Characteristics of Building Materials, or in 
accordance with the provisions of UL 723, Test for 
Surface Burning Characteristics of Btdldkig Materials. 
The specimen preparation and mounting procedures 



of ASTM E 2231, Specimen Preparation and Mounting 
of Pipe and Duct Insulation Materials to Assess 
Surface Burning Characteristics, shall be used. Air 
duct coverings and linings shall not flame, glow, 
smolder, or smoke when tested in accordance with 
ASTM C 411, Hot-Surface Performance of High- 
Temperature Thermal Insulation, at the temperature 
to which they are exposed in service. In no case shall 
the test temperature be below 250T (121 °C). 

Factory-made air ducts and faced insulations 
intended for installation on the exterior of ducts shall 
be legibly printed with the name of the manufacturer, 
the thermal resistance (R) value at installed 
thickness, and the flame-spread index and smoke 
developed index of the composite material. 

605. 1 [For OSHPD 1, 2, 3(surgical clinics) & 4] 

Thermal acoustical lining materials shall not be installed 
within ducts, terminal boxes, sound traps, and other in- 
duct systems serving areas such as operating, cesarean 
operating rooms, delivery rooms, post anesthesia care 
units, cystoscopy, cardiac cath labs, nurseries, intensive 
care units, newborn intensive care units, and airborne 
infection Isolation rooms unless terminal filters with 90 
percent average efficiency based on ASHRAE Standard 
52.2-1992 or minimum efficiency rating value (MERV) of 
14 are installed downstream of the duct lining. 

605.2 [For OSHPD 1, 2 & 4] Thermal or acoustical 
lining materials shall not be installed within ducts which 
are downstream of the 99.97 percent high-efficiency 
particulate air (HEP A) filter or with minimum efficiency 
rating value (MERV) of 17 required in Section 408.2.1 for 
protective environment rooms. 

606.0 Smoke Dampers, Fire Dampers, and Ceiling 
Dampers. 

606.1 Smoke Dampers. Smoke dampers shall 
comply with the standards for leakage-rated 
dampers referenced in Chapter 17, and shall be 
installed in accordance with approved manufacturer's 
installation instructions when required by the 
Building Code. Smoke dampers shall be labeled by 
an approved agency. 

606.2 Fire Dampers. Fire dampers shall comply 
with the standard for fire dampers referenced in 
Chapter 17, and shall be installed in accordance with 
the approved manufacturer's installation instructions 
when required by the Building Code. Fire dampers 
shall have been tested for closure under airflow 
conditions and shall be labeled for both maximum 
airflow permitted and direction of flow. When more 
than one damper is installed at a point in a single air 
path, the entire airflow shall be assumed to be 
passing through the smallest damper area. Fire 
dampers shall be labeled by an approved agency. 



96 



DUCT SYSTEMS 



606.2 - 608.4 



Ductwork shall be connected to damper sleeves 
or assemblies in accordance with the fire damper 
manufacturer's installation instructions. 

606.3 Ceiling Radiation Dampers. Ceiling radiation 
dampers shall comply with the standard for ceiling 
radiation dampers referenced in Chapter 17, and 
shall be installed in accordance with the manu- 
facturer's approved installation instructions in the 
fire-resistive ceiliag element of floor-ceiling and roof- 
ceiling assemblies when required by the Building 
Code. Fire dampers not meeting the temperature 
limitation of ceiling radiation dampers shall not be 
used as a substitute. Ceiling radiation dampers shall 
be labeled by an approved agency. 

606.4 IVIuitiple Arrangements. When size requires 
the use of multiple dampers, the installation shall be 
framed in an approved manner to ensure that the 
dampers remain in place. 

606.5 Access and Identification. Dampers shall be 
provided with an approved means of access large 
enough to permit inspection and maintenance of the 
damper and its operating parts. The access shall not 
impair fire-resistive construction. Access shall not 
require the use of tools, keys, or special knowledge. 
Access points shall be permanently identified on the 
exterior by a label with letters not less than 1/2 inch 
(12.7 mm) in height reading: SMOKE DAMPER or 
FIRE DAMPER. Access doors in ducts shall be tight 
fitting and suitable for the required duct construction. 

606.6 Freedom from Interference. Dampers shaU be 
installed in a manner to ensure positive closing or 
opening as required by function. Interior liners or 
insulation shall be held back from portions of a 
damper, its sleeve, or adjoining duct that would 
interfere with the damper's proper operation. Exterior 
materials shall be installed so as to avoid interference 
with the operation or maintenance of external 
operating devices needed for proper function. 

606.7 Temperature Classification of Operating 
Elements. Fusible links, thermal sensors, arid 
pneumatic or electric operators shall have a 
temperature rating or classification as required by 
the Building Code. 

606.8 When the automatic activation of a smoke damper or 
a combination smoke-fire damper occurs,the HVAC system 
serving such dampers shall immediately shut down. 

Exceptions: 

1. HVAC systems that are part of an engineered 
smoke evacuation system. 

2. Where the, automatic activation causes all the 
smoke dampers and combination smoke-fire 



dampers to close in the enclosed space having a 
common atmosphere where openings are required 
to be protected. 

3. Where analysis demonstrates shutoff would 
create a greater hazard. 

The HVAC system shall not be restarted again until all 
the dampers are reset and fully opened. 

607.0 Ventilating Ceilings. 

607.1 General. Perforated ceilings may be used for 
air supply within the limitations of this section. Exit 
corridors, when required to be of fire-resistive 
construction by the Building Code, shall not have 
ventilating ceilings. 

607.1.1 [For OSHPD 1, 2, 3 & 4] Ventilating 
ceilings are not permitted in health facilities. 

607.2 Requirements. Ventilating ceilings shall 
comply with the following provisions: 

607.2.1 Suspended ventilating ceiling material 
shall have a Class I flame-spread classification on 
both sides, determined in accordance with the 
Building Code. Suspended ventilating ceiling 
supports shall be of noncombustible materials. 

607.2.2 Lighting fixtures recessed into 
ventilating ceilings shall be of a tj^e approved 
for that purpose. 

608.0 Use of Under-Floor Space as Supply Plenum 
for Dwelling Units. 

An under-floor space may be used as a supply plenum, 
provided: 

608.1 The use of under-floor space shall be limited to 
dwelling uruts not more than two stories in height. 
Except for the floor immediately above the under- 
floor plenum, supply ducts shall be provided 
extending from the plenum to registers on other 
floor levels. 

Exception: In flood hazard areas, ujider-floor 
spaces shall not be used as supply plenums 
unless the flood opening requirements in the 
Building Code are satisfied. 

608.2 Such spaces shall be cleaned of all loose 
combustible scrap material and shall be tightly and 
substantially enclosed. 

608.3 The enclosing material of the under-floor 
space, including the sidewall insulation, shall be not 
more flammable than one (1) inch (25.4 mm) 
(nominal) wood boards (flame-spread index of 200). 
Installation of foam plastics is regulated by the 
Building Code, 

608.4 Access shall be through anoperung in the floor 



97 



608.4 - 609.0 



2007 CALIFORNIA MECHANICAL CODE 



and shall be not less than twenty-foiir (24) inches by 
twenty-four (24) inches (610 mm x 610 mm). 

608.5 A furnace supplying warm air to tinder-floor 
space shall be equipped with an automatic control 
that will start the air-circulating fan when the air in 
the furnace bonnet reaches a temperature not higher 
than 150°F (66°C). Such control shall be one that 
cannot be set higher than 150°F (66°C). 

808.6 A furnace supplying warm air to such space 
shall be equipped with an approved temperature 
limit control that will limit outlet air temperature to 
200T (93°C). 

608.7 A noncombustible receptacle shall be placed 
below each floor opening into the air chamber, and 
such receptacle shall conform to the following: 

608.7.1 The receptacle shall be securely suspended 
from the floor members and shall be not more 
than eighteen (18) inches (457 mm) below the 
floor opening. 

608.7.2 The area of the receptacle shall extend 
three (3) inches (76 mm) beyond the opening on 
all sides. 

608.7.3 The perimeter of the receptacle shall have 
a vertical lip at least one (1) inch (25.4 mm) high 
at the open sides if it is at the level of the bottom 
of the joists, or three (3) inches (76 mm) high if the 
receptacle is suspended. 

608.8 Floor registers shall be designed for easy 
removal in order to give access for cleaning the 
receptacles. 

608.9 Exterior walls and interior stud partitions 
shall be fire-stopped at the floor. 

608.1 Each wall register shall be cormected to the 
air chamber by a register box or boot. 

608.1 1 A duct coiiforming with Section 602.0 shall 
extend from the furnace supply outlet at least six (6) 
inches (152 mm) below combustible framing. 

608.1 2 The entire groimd surface of the under-floor 
space shall be covered with a vapor barrier having a 
minimum thickness of four (4) mils (0.1016 mm) and 
a flame-spread index of 200 or less. 

608.13 Fuel-gas lines and plumbing waste cleanouts 
are not located within the space. 



supply-air duct served by such equipment. Smoke 
detectors shall be labeled by an approved agency 
approved and listed by California State Fire Marshal for 
air duct installation and shall be installed in 
accordance with the manufacturer's approved 
installation instructions. Such devices shall be 
compatible with the operating velocities, pressures, 
temperatures, and humidities of the system. Where 
fire-detection or alarm systems are provided for the 
building, the smoke detectors required by this section 
shall be supervised by such systems and installed in 
accordance with NFPA 71 and the California Building and 
Fire Codes. 

Exceptions: 

(1) When the space supplied by the air-moving 
equipment is served by a total coverage 
smoke-detection system complying with the 
California Fire Code, interconnection to such 
system may be used to accomplish the 
required shutoff . 

(2) Automatic shutoff is not required when all 

occupied rooms served by the air-handling 
equipment have direct exit to the exterior 
and the travel distance does not exceed 100 
feet (30,480 mm). 

(3) Automatic shutoff is not reqtdred for Group 
R, Division 3 and Group U Occupancies. 

(4) Automatic shutoff is not required for 
approved smoke-control systems or where 
analysis demonstrates shutoff would create 
a greater hazard, such as may be encountered 
in air-moving equipment supplying 
specialized portions of Group H 
Occupancies. Such equipment shall be 
required to have smoke detection with 
remote indication and manual shutoff 
capability at an approved location. 

(5) Smoke detectors that are factory installed in 
listed air-moving equipment may be used in 
lieu of smoke detectors installed in the 
main supply-air duct served by such 
equipment. 



609.0 Automatic Shutoffs. 

Air-moving systems suppljmig air in excess of 2,000 
cubic feet per minute (944 L/s) to enclosed spaces 
within buildings shall be equipped with ah automatic 
shutoff. Automatic shutoff shall be accomplished by 
interrupting the power source of the air-moving 
equipment upon detection of smoke in the main 



98 



V. 



TABLE 6-1 Duct Construction for 4 foot Duct Lengths 



a 

c 
o 

H 
CO 

< 

CO 

-i 
m 

CO 



2" w.g. 

STATIC 
POS.ORNEG. 



DUCT CONSTRUCTION TABLE 6-1 FOR 4 FT. DUCT LENGTHS 



TRANSVERSE JOINT REINFORCEMENT 



INTERMEDIATE 
REINFORCEMENT 



© 



© 



© 



© 



© 



© 



© 



© 



© 



® 



® 



12 



DUCT 
DIM. 



< 

H 
O 
3 
O 



MAX— >- 3 I-— 



X 

< 

s 

o 

z 

o 
< 

Q. 
CO 

IL 

z 

LU 
Of 



mm. 



Ul 

o 
o 

UJ 

o 
o 
o 

UL 



UJ 



DRIVE SLIP T-3 

* 

MAXt-H 3" I— 
HEMMED "S" SLIP T-6 




11 




^7 



T-24 T-25a 



1/2" H 1— 



STANDING S (BAR 
REINFORCED) T-13 



SLIP 
GAGE 



BACKUP 





(WITH GASKET) 



•H-H 



B h— 



a 



L-T 

OR C 



STANDING S 
T-10 



STANDING S 
T-12 



STANDING S (ANGLE 
REINFORCED) T-14 



H = 1-3/8" 

(WITH GASKET) 



T-24a 



ANGLE 



ZEE 



10" dn 



26 



None 



24 



None 



HxT 



HxT 



HxT+HR 



H = 15 



HxT 



HxT{MIN) 



HxBxT(MIN) 



11 "-20" 



21 "-28" 



29"-30 " 



31»-42" 



43"-48 " 



49"-60" 



26 



26 



26 



24 



22 



24 



4" 



24 



1x22ga. 



1x24 ga. 



IxVs 



24 



1 Vs X 20 ga. 



1 X 20 ga. or 
1'^x22ga. 



24 



1 "/sxISga. 



1 x 18ga. or 
1 '/i!X20ga. 



NOT 
USED 



26 ga. 



1 x22ga. 



1x%x18ga. 



24 



24 



24 



1 %x18ga. 



1 VaxISga. 



1 %x18ga. 



1 % X 18 ga. 



iyzx18ga. 



1 i4x18ga. 



24 ga. 



1%x22ga. 
1%x%Bar 



1 yzx20ga. 



22 ga 



1 % X 20 ga. 
iVzxl^Bar 



20 ga. 



1% x22ga. 
I'/ix'/sBar 



22 ga. 



iVzxISga. 



1 V^x20ga. 



iy4Xl2ga. 

or 

1x14 HR 



^'AxVs 



iy2X%x16ga. 



61 "-72" 



73"-84 " 



85"-96 " 



24 



22 



22 



24 



1% x18ga. 
lyzxVsBar 



2xy6 



iVzx^xys 



22 



NOT GIVEN 



NOT GIVEN 



2" 



22 



2y6x20ga. 
2xV4Angle 



20 ga. + rods 



NOT GIVEN 



2xyi6 



2 x 1 '/s X 12 ga. 



CO 
CO 



NOTES: 

I. *Mcans use backrup member from columns U or 12 Hxceptiom the drive only 

requires back-up over IS length. 
2,. Spacing in column 3 refers to joint-to-joint, joinl-to-intemiediate, or 

intennediate-to-intermediate. 

3. The same sheet thickness must be used on all sides of duct- Each duct 
dimension. Avidth, or depth, controls the minimum reinforcement requirements 
for that particular side. 

4. Duct sides 19" wide and larger which have more than ten square feet of 
unbraced panel shall be beaded or crossbroken unless tite ducts will have 
external insulation or internal liner. The applies to duct of 20 ga. or less. 



Contents of the narrow scope tables and these notes do not constitute all 
requirements for the con.stniction\s compliance. Complete details are provided 
in the manual entitles HVAC Duct Construction Standards, Metal and Flexible. 
The manual is available from local SM ACNA chapter offices of the National 
Association office; inquire for tenu-;. 

Construction conforming to the standard does not prevent .some haditionally 
acceptable rumble (noise) under sudden pressure change conditions such as statt 
up and shut down of sy.siems. 



COMMENT: 

Conshuction tables are prepared in "narrow scope" for 2" water gage and I " water 
gage pressure classification. These tables have been produced for the convenience of 
those contractors or engineers who wish to have fewer options. 
Sheet Metal and Air Conditioning 
Contractors' National Association, Chantilly, Va. 



CD 



o 
o 



TABLE 6-2 Duct Construction for 5 Foot Duct Lengths 



2" w.g. 

STATIC 
POS.ORNEG. 



© 



DUCT 
DEVI. 



10" dn 



11 "-20" 



21 "-26" 



27"-30 " 



31 "-36" 



37 "-54 " 



55"-60 " 



61 "-72" 



73"-84 " 



85"-96 " 







< 

o 

H 
O 

o 



26 



26 



26 



24 



22 



24 



24 



22 



22 



20 



© 



o 

z 

u 



None 



214' 



2'/2' 



2W 



2^2' 



2W 



© 



m 



o 

§ 
u 



DUCT CONSTRUCTION TABLE 6-2 FOR 5 FT. DUCT LENGTHS 



TRANSVERSE JOINT REINFORCEMENT 



© 



MAX-—- 3 I- — 

,^<& •' I—. 

DRIVESLIPT-3 
MAXt— i 3" I— 



HEMMED "S" SLIP T-6 



SLIP 
GAGE 



24 



24 



24 



24 



24 



24 



24 



24 



22 



22 



BACKUP 



None 



© 




STANDINGS 
T-10 



HxT 



1x22ga. 



1 Va X 20 ga. 



1 Vs X 18 ga. 



1 % X 18 ga. 



1 %x18ga. 



1 ysx18ga. 



NOT GIVEN 



© 




STANDINGS 

T-12 



HxT 



1 x22ga. 



1 X 20 ga. 



1 x 18 ga. 



1 !4x18ga. 



1!4x18ga. 



114x18ga. 



NOT GIVEN 



® 




STANDING S (BAR 
REINFORCED) T-13 




STANDING S (ANGLE 
REINFORCED) T-14 



H X T + HR 



NOT 
USED 



1 % X 22 ga. 
1'/2X%Bar 



1 % X 20 ga. 
iy2xy8Bar 



iy5x22ga. 
1>/2X>/8Bar 



1 %x18ga. 
iy2x'/& Angle 



2 % X 20 ga. 
2 X % Angle 



© 



T-24 T-25a 



T-25b 

H = 1-3/8" 
(WITH GASKET) 



H X 1 %' 



26 ga. 



24 ga. 



22 ga 



22 ga. 



22 ga. + rods 



20 ga. + rods 



1/2" H h- 



(WITH GASKET) 



T-24a 



HxT 



1 X 22 ga. 



1 '/2x20ga. 



1 V^xIBga. 



NOT GIVEN 



INTERMEDIATE 
REINFORCEMENT 



® 



-H— ! 



ANGLE 



HxT(MIN) 



tx'A 



1 M X 12 ga. 

or 

1x% 



H^x'/s 



2xy6 



2X^16 



L 



rr 



L-1 

OR C 



HxBxT(MIN) 



1x%x18ga. 



iy2X%x16ga. 



iy2x%xy8 



2x1 '/6x12ga. 



*Means use back-up member from columns 11 or 12 Exception: the drive only 
, reguires back-up over 18" lengtli. . 
Spacing in column 3 refers to joint-to-joinl, joint-lo-intenncdialc, or 
intemiediaic-to-intcrmcdiatc. 

The same sheet thickness must be used on all sides of duct. Each duct 
dimension, width, or depth, controls the minimum reinforcement requirements 
for that particular side. 

Duct sides 19" wide and larger whicli have more than ten square feet of 
unbraced panel shall be beaded or crossbroken unless the ducis will have 
external insulation or internal liner. The applies to duct of 20 ga.ot less. 



Contents of the narrow scope tables and these notes do not constitute all 
requirements for the constmction's compliance. Complete details are provided 
in the manual entitles HVAC Duct Construction Standards, Metal and Flexible. 
The manual is available from local SMACNA chapter ofllces of the National 
Association oHlce; inquire &>t lenns. 

Construction conforming to the standard does not prevent some traditionally 
acceptable rumble (noise) under sudden pr^sure change conditions such as start 
up and shut down of systems. 



COMMENT: 

Construction tables are prepared in "narrow scope" for 2" water gage and I " water 
gage pressure classification. These tables have been produced for the convenience of 
those contractors or engineers who wish to have fewer options. 
Sheet Metal and Air Conditioning 
Contractors' National Association, Chantilly. Va. 



H 
g; 

(D 

I 



o 
o 

O 

> 



O 
33 



m 
o 

> 

o 
> 

r- 
O 

o 
o 
m 



DUCT SYSTEM 



Table 6-3 -Table 6-5 



RECTANGULAR ALUMINUM DUCT 
ADAPTED FROM 3" W.G. (750 Pa) OR LOWER 



TABLE 6-3 
THICKNESS ADJUSTMENTS 


Galv. Steel Ga. (mm) 
nominal 


28 (0.48) 


26 (0.55) 24 (0.70) 


22 (0.78) 20 (1.00) 


18 (1.31) 


16 (1.61) 


Min. Alum, esquivalent* (mm) 


0.023 
(0.58) 


0.027 0.034 
(0.69) (0.86) 


0.043 0.052 
(1.09) (1.32) 


0.067 
(1.70) 


0.083 
(2.11) 


Commercial size (mm) 


0.025 
(0.60) 


0.032 0.04 
(0.80) (1.00) 


0.05 0.063 
(1.27) (1.60) 


0.071 
(1.80) 


0.09 
(2.29) 


Lbs wt/Sf. Alum. 




Consult Appendix-5 for Weights 







♦Alloy 3003-H-14. 



TABLE 6-4 
DIMENSION ADJUSTMENTS 


Galv. Rigidity Class 


A B C D E F G 


H 1 


J 


K 


L 


Alum. dim. per Galv. Class 


C E E F H 1 1 „ 


K 


** 


*• 


** 



** Calculate an effecti\w I = 3 x that used for steel. 



TABLE 6-5 
REINFORCEMENTS 



Steel Angle Size, 
Inches (mm) 



Equivalent Alum.*** 
Cod Angle Size, Inches 



Steel Bar 



Alum. Bar*** 



1 x 1 x 16 Ga. 
(25x25x1.61) 



11/4x11/4x1/8 
(31.8x31.8x3.2) 



1x1/8 11/2x1/8 on 1/4x3/16 

(25x3.2) (38.1x38.1 or 













31.8x4.8) 


1x1x1/8 
(26 X 25 X 3.2) 


D 


11/2x11/2x1/8 
(38.1x38.1x3.2) 




11/2x1/8 
(38.1 X 3.2) 


11/2x1/8 or 11/4x3/16 
(38.1x38.1 or 
31.8x4.8) 


11/4x11/4x1/8 
(31.8x31.8x3.2) 


F 


13/4x13/4x1/6 
(44.5x44.5x3.2) 








11/2x11/2x1/8 
(31.8x31.8x3.2) 


G 


21/2x21/2x1/8 
(63.5x63.5x3.2) 








2x2x1/8 
(51 x 51 X 3.2) 


H 


21/2 X 21/2 x 3/16 
(63.5x63.5x4.8) 








2x2x3/16 
(51x51x4.8) 


1 


21/2 X 21/2 X 3/8 or 
(63.5x63.5x7.9 Of 


3x3x1/4 
76.2x76.2x6.4) 




2x2x1/4 
(51 X 51 X 6.4) 


J 


21/2 x 21/2 x 3/8 or 
(63.5x63.5x7.9 or 


3x3 
76.2 


x1/4 

X 76.2x6.4) 




21/2x21/2x3/16 
(63.5 X. 63.5 x 4.8) 


K 


3 X 3 X 3/8 or 31/2 X 
(76.2 X 76.2 X 9.5 or 


31/2 
88.9 


x1/4 

X 88.9x6.4) 





•-Alloy 6061-T6 Stnengtti normally. 

Any aluminum shape substituted must have a moment of Inertia three times that of steel and have 30,000 psi minimum yield strength. 

SMACNA HVAC Duct Construction Standards Metal and Flexible - Second Edition 



101 



Table 6-6A 



2007 CALIFORNIA MECHANICAL CODE 



TABLE 6-6 A (l-P Units) 
Minimum Duct Insulation R Value" Cooling and Heating Only Supply Ducts and Return Ducts 



Climate Zone 



Duct Location 



Envelope HDD65 CDD50 Exterior Ventilated Unvented Unvented Uncon- Indirectly Buried 

Criteria Table Attic Attic w/ Attic w/ ditioned Con- 

Backloaded Roof Space' ditioned 

Ceiling Insulation' Space" 

Heating-Only Ducts 



5-1 to 5-7 


0-1,800 


aU 


5-8 to 5-12 


1,801-3,600 


all 


5-13 to 5-15 


3,601-5,400 


aU 


5-16 to 5-18 


5,401-7,200 


aU 


5-19 to 5-20 


7,201-9,000 


aU 


5-21 to 5-22 


9,001-10,800 


aU 


5-23 


10,801-12,600 


an 


5-24 


12,601-16,200 


all 


5-25 


16,201-19,800 


all 


5-26 


19,801+ 


all 



5-15, 18, 20, 

22 to 26 
5-12, 14, 17, 

19,21 
5-7, 9, 11, 13, 

16 

5-4, 6, 8, 10 

5-3,5-5 

5-2 

5-1 



none 


none 


none 


R-3.5 


none 


none 


R-3.5 


none 


none 


R-6 


R-3.5 


none 


R-6 


R-6 


R-3.5 


R-8 


R-6 


R-6 


R-8 


R-6 


R-6 


R-8 


R-8 


R-6 


R-10 


R-8 


R-8 


R-10 


R-10 


R-8 




Cooling-Only 


Ducts 


R-1.9 


R-1.9 


R-1.9 



aU 


0-1,800 


R-1.9 


R-1.9 


R-1.9 


all 


1,801-3,600 


R-3.5 


R-1.9 


R-3.5 


aU 


3,601-5,400 


R-3.5 


R-3.5 


R-6 


aU 


5,401-7,200 


R-6 


R-6 


R-6 


aU 


7,201-9,000 


R-6 


R-6 


R-6 


aU 


9,001-10,800 


R-6 


R-6 


R-8 


all 


10,801+ 


R-8 


R-8 
Return Ducts 


R-8 



none 


none 


none 


none 


none 


none 


none 


none 


none 


none 


none 


none 


none 


none 


none 


R-3.5 


none 


none 


none 


R-3.5 


none 


R-3.5 


none 


R-3.5 


none 


R-6 


none 


R-6 


none 


R-6 


none 


R-6 


none 


R-6 


none 


R-6 


none 


R-8 


none 


R-6 



R-1.9 


R-1.9 


none 


none 


R-1.9 


R-1.9 


none 


none 


R-1.9 


R-1.9 


none 


none 


R-3.5 


R-1.9 


none 


none 


R-3.5 


R-3.5 


none 


R-3.5 


R-3.5 


R-3.5 


none 


R-3.5 


R-3.5 


R-3.5 


none 


R-3.5 



5-15 to 5-26 



all climates R-3.5 



R-3.5 



R-3.5 



none 



Notes: 

" Insulation R-values, measured in (h-#-°F)/Btu, are for the insulation as installed and do not include film resistance. The 
required minimum thicknesses do not consider water vapor transmission and possible surface condensation. Where exterior 
walls are used as plenum walls, wall insulation shall be as required by the most restrictive condition. 
Insulation resistance measured on a horizontal plane in accordance with ASTM C518 at a mean temperature of 75°F at the 
installed thickness. 

' Includes crawl spaces, both ventilated and nonventilated. 

' Includes return-air plenums with or without exposed roofs above. 

'' Vapor retarders shall be installed on supply ducts in spaces vented to the outside in geographic areas where the average sum- 
mer dewpoint temperature based on the 2-1/2 percent colimm of dry-bulb and mean coincident wet-bulb temperature 
exceeds 60°F (16°C). 

° Insvdation shall have an approved weatherproof barrier. 



102 



DUCT SYSTEMS 



Table 6-6B 



TABLE 6-6 B (l-P Units) 
Minimum Duct Insulation R Value" Combined Heating and Cooling Ducts 



Climate Zone 


Duct Location 


Envelope HDD65 


CDD50 


Exterior 


Ventilated 


Unvented 


Unvented 


Uncon- 


Indirectly 


Buried 


Criteria 








Attic 


Attic w/ 


Attic w/ Roof 


ditioned 


Conditioned 




Table 










Backloaded 
Ceiling 


Insulation" 


Space'" 


Space' 




5-1 


0-900 


10,801+ 


R-8 


'R-6 


R-8 


R-3.5 


R-3.5 


none 


R-3.5 


5-2 


0-900 


9,001-10,800 


R-6 


R-6 


R-8 


R-3.5 


R-3.5 


none 


R-3.5 


5-3 


0-900 


7,201-9,000 


R-6 


R-6 


R-6 


R-3.5 


R-3.5 


none 


R-3.5 


5-4 


0-900 


0-7,200 


R-6 


R-3.5 


R-6 


R-3.5 


R-1.9 


none 


R-3.5 


5-5 


901-1,800 


7,201+ 


R-6 


R-6 


R-6 


R-3.5 


R-3.5 


none 


R-3.5 


5-6 


901-1,800 


5,401-7,200 


R-6 


R-6 


R-6 


R-3.5 


R-3.5 


none 


R-3.5 


5-7 


901-1,800 


0-5,400 


R-3.5 


R-3.5 


R-6 


R-1.9 


R-1.9 


none 


R-1.9 


5-8 


1,801-2,700 


5,401+ 


R-6 


R-6 


R-6 


R-3.5 


R-3.5 


none 


R-3.5 


5-9 


1,801-2,700 


0-5,400 


R-6 


R-3.5 


R-6 


R-1.9 


R-1.9 


none 


R-1.9 


5-10 


2,701-3,600 


5,401+ 


R-6 


R-6 


R-6 


R-3.5 


R-3.5 


none 


R-3.5 


5-11 


2,701-3,600 


3,601-5,400 


R-6 


R-6 


R-6 


R-3.5 


R-3.5 


none 


R-1.9 


5-12 


2,701-3,600 


0-3,600 


R-3.5 


R-3.5 


R-3.5 


R-1.9 


R-1.9 


none 


R-1.9 


5-13 


3,601-5,400 


3,601+ 


R-6 


R-6 


R-6 


R-3.5 


R-3.5 


none 


R-3.5 


5-14 


3,601-5,400 


1,801-3,600 


R-6 


R-3.S 


R-6 


R-1.9 


R-3.5 


none 


R-1.9 


5-15 


3,601-5,400 


0-1,800 


R-3.5 


R-3.5 


R-3.5 


R-1.9 


R-1.9 


none 


R-1.9 


5-16 


5,401-7,200 


3,601+ 


R-6 


R-6 


R-6 


R-3.5 


R-3.5 


none 


R-3.5 


5-17 


5,401-7,200 


1,801-3,600 


R-6 


R-6 


R-6 


R-1.9 


R-3.5 


none 


R-3.5 


5-18 


5,401-7,200 


0-1,800 


R-6 


R-3.5 


R-3.5 


R-1.9 


R-3.5 


none 


R-3.5 


5-19 


7,201-9,000 


1,801+ 


R-8 


R-6 


R-6 


R-1.9 


R-3.5 


none 


R-3.5 


5-20 


7,201-9,000 


0-1,800 


R-6 


R-6 


R-6 


R-1.9 


R-3.5 


none 


R-3.5 


5-21 


9,001-10,800 


1,801+ 


R-8 


R-6 


R-6 


R-1.9 


R-6 


none 


R-3.5 


5-22 


9,001-10,800 


0-1,800 


R-8 


R-6 


R-6 


R-1.9 


R-3.5 


none 


R-3.5 


5-23 


10,801-12,600 


all 


R-8 


R-6 


R-6 


R-1.9 


R-6 


none 


R-6 


5-24 


12,601-16,200 


aU 


R-8 


R-8 


R-8 


R-1.9 


R-6 


none 


R-6 


5-25 


16,201-19,800 


aU 


R-10 


R-8 


R-8 


R-3.5 


R-6 


none 


R-6 


5-26 


19,801+ 


all 


R-10 


R-10 


R-8 


R-3.5 


R-8 


R-3.5 


R-6 



Notes: 

" Insulation R-values, measured in (h-ft^-°F)/Btu, are for the insulation as installed and do not include film resistance. The 

required minimum thicknesses do not consider water vapor transmission and possible surface condensation. Where exterior 

walls are used as plenum walls, wall insulation shall be as required by the most resfa'ictive condition. 

Insulation resistance measured on a horizontal plane in accordance with ASTM C518 at a mean temperature of 75°F at the 

installed thickness. 
' Includes crawl spaces, both ventilated and nonventilated. 
' Includes return air plenums with or without exposed roofs above. 
'' Vapor retarders shall be installed on cooling supply ducts in spaces vented to the outside in geographic areas where the average 

summer dewpoint temperature based on the 2-1/2 percent column of dry-bulb and mean coincident wet-bulb temperature 

exceeds 60°F (16°C). 
" Insulation shall have an approved weatherproof barrier. 



103 



Table 6-7 



2007 CALIFORNIA MECHANICAL CODE 



TABLE 6-7 
Duct Support 

A. Vertical Ducts 



inches x 25.4 = mm 
feet X 304.8 = m 



Maximum 

Side of 

Rectangular 

Duct 


Metal Strap or 
Angle Bracket 


Maximum 

Diameter 

of Round 

Ducts 


Strap 


24" 


1" X 1/8" strap' 


10" 


0.047" (No. 18 gauge) 
galvanized steel 2" wide' 


36" 


1" x 1" x 1/8" angle' 


20" 


0.058" (No. 16 gauge) 
galvanized steel 2" wide' 


48" 


1-1/8" X 1-1/8" X 1/8" angle" 


40" 


1/8" steel X 1-1/2"' 


60" 


1-1/2" X 1-1/2" X 1/8" angle' 


60" 


1/8" steel X 2"' 


Over 60" 


2" X 2" X 1/8" angle' 


Over 60" 


3/16" steel X 2"' 



B. Horizontal Ducts 



18" 


1" X 18 gauge' 


10" 


Same gauge as galvanized steel duct, 
1" wide or (No. 18 gauge galvanized 
steel wire) on 10' centers 


30" 


1" X 18 gauge' 


48" 


l"xl/8"' 


20" 
40" 


Same gauge as galvanized steel 
duct, 1" wide or (No. 8 gauge 
galvaiuzed steel wire) tied to 
1" galvanized steel band 
around duct on 10' centers 


60" 


1" X 1/8"' 


80" 


1" X 1/8"' 






60" 


Same gauge as galvanized steel 
duct, 1-1/2" wide on 6' centers 


Over 60" i 


ame gauge as galvanized steel 
duct, 1-1/2" wide on 4' centers 



C. Horizontal Ducts — Trapeze-Type Supports 


Maximum 

Diameter of Round 

Duct or Side of 

Rectangular Duct 


Horizontal 
Support 
Angle' 


Hanger 


36" 


1-1/2" X 1-1/2" X 1/8" 


1/4" round rod or 1" x 1" x 1/8" angle 


48" 


2"x2"xl/8" 


1/4" round rod or 1" x 1" x 1/8" angle 


60" 


2"x2"xl/8" 


5/16" roimd rod or 1" x 1" x 1/8" angle 


84" 


2"x2"xl/8" 


3/8" round rod or 1" x 1" x 1/8" angle 



Notes: 

' Spaced vertically not more than 12 feet on centers. 
' Spaced horizontally not more than 10 feet on centers. 
' Spaced not more than 8 feet on centers. 



104 



DUCT SYSTEMS 



Table 6-8 - Table 6-9 







TABLE 6-8 
Construction Details for Round and Flat-Ovai Ducts 


inches x 25.4 = mm 
■ 2"WC = 498Pa 
\ 10" WC = 2.5 kPa 


Duel Diameter 
Max. Width 
(In Inches) 


Aluminum 
B. & S. Gage 


STEEL — THICKNESS IN INCHES 
(STEEL — GALVANIZED SHEET GAUGE) 


GIRTH JOINTS' 


Pressure < 2" WC 


Pressure < 2" WC 


Pressure > 2" < 10" WC 


Pressure > 2" < 10" WC 


Minimum Girth 
Reinforcing, Maximum 
Spacing and Angle Size 


Round 


Round 


Flat-Oval 


Spiral Seam 


Longitudinal 
Seam 


Welded 
Fittings 


Up to 9 


24 


0.019 
(26) 


0.024 
(24) 


0.019 
(26) 


0.024 , 
(24) 


0,030 
(22) 


T SUp 


None 


Over 9 
Up to 14 


. 24 


0.019 
(26) 


0.024 
(24) 


0.024 
(24) 


0.030 
(22) 


0.036 
(20) 


4" SUp 


None 


Over 14 
Up to 23 


22 


0.024 
(24) 


0.030 
(22) 


0.024 
(24) 


0.030 
■ (22) 


0.036 
(20) 


4" Slip 


None 


Over 23 
Up to 37 


20 


0.030 
(22) 


0.036 
(20) 


0.030 
(22) 


0.036 
(20) 


0.036 
(20) 


4" SHp 


None 


Over 37 
Up to 51 


18 


0.036 
(20) 


0.047 
(18) 


0.036 
(20) 


0.036 
(20) 


0.047 
(18) 


1-1/4" X 1-1/4" X 1/8" 
Flange 


1-1/4" X 1-1/4" X 1/8" 
on 72" 


Over 51 
Up to 61 


16 


0.047 
(18) 


0.058 
(16) 


X 

(18) 


0.047 
(18) 


0.047 
Flange 


1-1/4" X 1-1/4" X 1/8" 
on 72" 


1-1/4" X 1-1/4" X 1/8" 


Over 61 
Up to 84 


14 


0.058 
(16) 


0.070 
(14) 


X 


0.058 
(16) 


0.058 
(16) 


1-1/2" X 1-1/2" X 1/8" 
Flange 


1-1/2" X 1-1/2" X 1/8" 
on 48"" 



Notes: 



For pressure < 2 inches WC (498 Pa), any of the following joints are acceptable: butt sHp; pipe sHp; pipe lock; roll slip; snap 
sHp; plenum lock; and companion flange. 

Acceptable longitudinal seams for pressure < 2 inches WC (610 mm): Acme (grooved); snap lock; standing; and spiral.. 



TABLE 6-9 
Tiiici<ness of IVietai Ducts and Plenums Used for Heating or Cooling for a Single-Dwelling Unit 





GALVANIZED STEEL 




Minimum 

Thickness, 

Inches (mm) 


Equivalent 

Galvanized Sheet 

Gauge No. 


Approximate 

Aluminum 

B.&S. Gauge 


Round ducts and enclosed 
rectangular ducts 
14" (356 mm) or less 
Over 14" (356 mm) 


0.013 (0.33) 
0.016 (0.41) 


30 
28 


26 

24 


Kxposed rectangular ducts 
14" (356 mm) or less 
Over 14" (356 mm) 


0.016(0.41) 
0.019 (0.48) 


28 
26 


24 
22 



105 



Table 6-1 2007 CALIFORNIA MECHANICAL CODE 

TABLE 6-10 
Alternate Supports for Factory-Made Air Ducts 

Maximum Support 
Class 1 Duct Material Minimum Support Material Spacing, Feet 

Rigid round fibrous No. 26 gauge x 5/8" 6 

wide galvaruzed iron strap 

Corrugated metal No. 18 gauge galvanized 6 

iron wire 

Flexible No. 26 gauge x 1-1/2" 4 

wide galvariized iron strap 



inches x 25.4 = mm 
feet x 304.8 = m 



106 



CHAPTER 7 

COMBUSTION AIR 



701.0 Air for Combustion and Ventilation. 

701.1 General. 

701.1.1 Air for combustion, ventilation, and 
dilution of flue gases for gas utilization 
equipment installed in buildings shall be 
obtained by application of one of the methods 
covered in Sections 701.2 through 701.8.3. Gas 
utilization equipment of other than natural draft 
and Category I vented appliances shall be 
provided with combustion, ventilation, and 
dilution air in accordance with the equipment 
manufacturer's instructions. Where infiltration 
does not provide the necessary air, outdoor air 
shall be introduced in accordance with methods 
covered in Sections 701.4 through 701.8.3. 

Exceptions: 

(1) This provision shall not apply to direct- 
vent appliances. 

(2) Type 1 clothes dryers that are provided 
with makeup air in accordance with 
Section 504.3.2. 

701.1.2 Gas appliances of other than natural 
draft design and other than Category I vented 
appliances shall be provided with combustion, 
ventilation, and dilution air in accordance with 
the appliance manufacturer's instructions. [NFPA 
54: 9.3.1.2] 

701.1.3 Where used, a draft hood or a barometric 
draft regulator shall be installed in the same room 
or enclosure as the equipment served so as to 
prevent any difference in pressure between the 
hood or regulator and the combustion-air supply. 
[NFPA 54: 9.3.1.4] 

701.1.4 Makeup air requirements for the 
operation of exhaust fans, kitchen ventilation 
systems, clothes dryers, and fireplaces shall be 
considered in determining the adequacy of a 
space to provide combustion-air requirements. 
[NFPA 54: 9.3.1.5] 

701.2 Indoor Combustion Air. The required volume 
of indoor air shall be determined in accordance with 
the method in section 701.2.1 or 701.2.1.1, except that 
where the air infiltration rate is known to be less than 
0.40 ACH, the method in Section 701.2.1.1 shall be 
used. The total required volume shall be the sum of the 
required volume calculated for all appliances located 
within the space. Rooms communicating directly with 
the space in which the appliances are installed through 



openings not furnished with doors, and through 
combustion air openings sized and located in 
accordance with Section 701.3.1, are considered a part 
of the reqxured volume. [NFPA 54: 9.3.2] 

701.2.1 Standard Method. The minimum 
required volume shall be fifty (50) cubic feet per 
1,000 Btu/hour (4.8 mVkW) [NFPA 54: 9.3.2.1]. 

701.2.1.1 Known Air Infiltration Rate 
Method Equations. 

Equation 701.2.1.1(a): 

Required Volume ^ther ^ (21 ft.' /ACH) x 
(W/ 1,000 Btu/hr) 

Equation 701.2.1.1(b): 

Required Volume fi,„ s (15 ft.^ /ACH) x 
(I;-„„/l,OOOBtu/h.) 

WHERE: 

Igjf,^,. = all appliances other than fan-assisted 
input in Btu per hoxu: 

lf„„ = fan-assisted appliance input in Btu 
per hour 

ACH = air change per hour (percent of 
volume of space exchanged per 
hour, expressed as a decimal) 

701.2.2 Known Air Infiltration Rate Method. 

Where the air infiltration rate of a structure is 
known, the minimum required volume shall be 
determined as follows [NFPA 54: 9.3.2.2]: 

(1) For appliances having other than fan- 
assisted combustion systems: calculate using 
equation 701.2.1.1(a) but no smaller than 
thirty-five (35) cubic feet per 1,000 Btu/hour 
(3.4 mVkW). [NFPA 54: 9.3.2.2(1)] 

(2) For fan-assisted combustion system appliances: 
calculate using equation 701.2.1.1(b) but no 
smaller than twenty-five (25) cubic feet per 
1000 Btu/hour (2.4 mVkW). [NFPA 54: 
9.3.2.2(2)] 

(3) For purposes of this calculation, an 
infiltration rate greater than 0.60 ACH shall 
not be used in the equations. [NFPA 54: 
9.3.2.2(3)] 

701.3 Indoor Opening Size and Location. 

701.3.1 Openings used to connect indoor spaces 
shall be sized and located in accordance with the 
following [NFPA 54: 9.3.2.3]: 

(1) Combining spaces on the same story. Each 
opening shall have a minimum free area of 1 
in.V 1,000 Btu/h. (220 mmVkW) of the total 



I 



107 



701.3-701.8 



2007 CALIFORNIA MECHANICAL CODE 



input rating of all gas utilization equipment 
in the space, but not less than 100 in.^ (0.06 m^). 
One opening shall commence within twelve 
(12) inches (300 mm) of the top, and one 
opening shall commence within twelve (12) 
in. (300 mm) of the bottom, of the enclosure. 
(See Figure 7-1.) The nainitnum dimension of 
air openings shall be not less than three (3) 
inches (80 mm). [NFPA 54: 9.3.2.3(1)] 

(2) Combining spaces in different stories. The 
volumes of spaces in different stories shall be 
considered as communicating spaces where 
such spaces are cormected by one or more 
openings in doors or floors having a total 
minimum free area of 2 in. V 1,000 Btu/h 
(4,400 mmVkw) of total input rating of all 
gas utilization equipment. [NEFPA 54:9.3.2.3(2)] 

701.4 Outdoor Combustion Air. Outdoor combustion 
air shall be provided through opening(s) to the 
outdoors in accordance with the methods in Section 
701.4.1 or 701.4.2. The minimum dimension of air 
openings shall not be less than three (3) inches (80 
mm). [NFPA 54:9.3.3] 

701.4.1 Two Permanent Openings lUletliod. 

Two permanent openings, one commencing 
within twelve (12) inches (300 mm) of the top 
and one commencing within twelve (12) inches 
(300 mm) of the bottom of the enclosure, shaU be 
provided. The openings shall communicate 
directly, or by ducts, with the outdoors or spaces 
that freely communicate with the outdoors, as 
follows [NFPA 54:9.3.3.1]: 

(1) Where directly communicating with the 
outdoors or where communicating to the 
outdoors through vertical ducts, each 
opening shall have a minimtim free area of 1 
in.V4,000 Btu/h (550 mmVkW) of total 
input rating of all equipment in the 
enclosure. (See Figures 7-2 and 7-3.) [NFPA 
54:9.3.3.1(1)] 

(2) Where communicating with the outdoors 
through horizontal ducts, each opening shall 
have a minimum free area of 1 in. V 2,000 
Btu/h (1,100 mmVkW) of total input rating 
of all equipment in the enclostire. (See Figure 
7-4.) [NFPA 54:9.3.3.1(2)] 

701.4.2 One Permanent Opening Methiod. One 

permanent opening, commencing within twelve 
(12) inches (300 mm) of the top of the enclosure, 
shall be provided. The equipment shall have 
clearances of at least one (1) inch (25 mm) from 
the sides and back and six (6) inches (160 mm) 
from the front of the appliance. The opening shall 
directly comm.imicate. with the outdoors or shall 



communicate through a vertical or horizontal 
duct to the outdoors or spaces that freely 
commtinicate with the outdoors (see Figure 7-5) 
and shall have a minimum free area of [NFPA 
54: 9.3.3.2]: 

(1) 1 in.2/3,000 Btu/h (700 mmVkW) of the 
total input rating of all equipment located in 
the enclosure, and 

(2) Not less than the sum of the areas of all vent 
connectors in the space. [NFPA 54:9.3.3.2] 

701.5 Combination Indoor and Outdoor Combustion 
Air. The use of a combination of indoor and outdoor 
combustion air shall be in accordance with Sections 
701.5.1 through 701.5.3. [NFPA 54:9.3.4] 

701.5.1 Indoor Openings. Where used, openings 
connecting the interior spaces shall comply with 
Section 701.3.1. [NFPA 54:9.3.4(1)] 

701.5.2 Outdoor opening(s) shall be located in 
accordance with Section 701.4. [NFPA 
54:9.3.4(2)] 

701.5.3 Outdoor Opening(s) Size. The outdoor 
opening(s) size shall be calculated in accordance 
with the following [NFPA 54:9.3.4(3)]: 

(1) The ratio of interior spaces shall be the 
available volume of all communicating 
spaces divided by the required volume. 
[NFPA 54:9.3.4(3)(a)] 

(2) The outdoor size reduction factor shall be 1 
minus the ratio of interior spaces. [NFPA 
54:9.3.4(3)(b)] 

(3) The minimum size of outdoor opening(s) 
shall be the full size of outdoor opening(s) 
calculated in accordance with Section 701.4, 
multiplied by the reduction factor. The 
minimum dimension of air openings shall 
not be less than three (3) inches (80 mm). 
[NFPA 54:9.3.4(3)(c)] 

701.6 Engineered Installations. Engineered 
combustion air installations shall provide adequate 
supply of combustion, ventilation, and dilution air 
and shall be approved by the Authority Having 
Jurisdiction. [NFPA 54:9.3.5] 

701.7 IVIechanical Combustion Air Supply. Where 
all combustion air is provided by a mechanical air 
supply system, the combustion air shall be supplied 
from outdoors at the minimum rate of 0.35 iee^/mm 
per 1,000 Btu/h (0.034 mVmin per kW) for all 
appliances located within the space. [NFPA 54:9.3.6] 

701.8 Mechanical Combustion Air Requirements. 

701.8.1 Where exhaust fans are installed, 
additional air shall be provided to replace the 
exhausted air. [NFPA 54:9.3.6.1] 



I 



I 



I 



108 



COMBUSTION AIR 



701 .8 - Figure 7-1 



701 .8.2 Each of the appliances served shall be 
interlocked to the mechanical air supply 
system to prevent main burner operation 
where the mechanical air supply system is not 

I in operation. [NFPA 54:9.3.6.2] 

701.8.3 Where combustion air is provided by 
the building's mechanical ventilation system, the 
system shall provide the, specified combustion 
air rate in addition to the required ventilation 

I air. [NFPA 54:9.3.6.3] 

701.9 Louvers, Grilles and Screens. 

I (A) Louvers and Grilles. The required size of 
openings for combustion, ventilation, and dilution 
air shall be based on the net free area of each 
opening. Where the free area through a design of 
louver, grille or screen is knov/n, it shall be used in 
calculating the size opening required to provide the 
free area specified. Where the louver and grille 
design and free area are not known, it shall be 
assumed that wood louvers will have a 25 percent 
free area and. metal louvers and grilles will have a 75 
percent free area. Nonmotorized louvers and grilles 
shall be fixed in the open position. [NFPA 54:9.3.7.1] 

(B) Minimum Screen IVIesh Size. Screens shall not 
be smaller than 1/4-inch mesh. [NFPA 54:9.3.7.2] 

(C) Motorized Louvers. Motorized louvers shall be 
interlocked with the equipment so they are proven in 
the full open position prior to main burner ignition 
and during main burner operation. Means shall be 
provided to prevent the main burner from igniting 
should the louver fail to open during burner startup 
and to shut down the main burner if the louvers 
close during burner operation. [NFPA 54:9.3.7.3] 

701.10 Combustion Air Ducts. Combustion air ducts 
shall comply with the following [NFPA 54:9.3.8]: 

(1) Ducts shall be of galvanized steel or a material 
having equivalent corrosion resistance, strength, 
and rigidity. [NFPA 54:9.3.8.1] 

Exception: Within dwellings units, 
unobstructed stud and joist spaces shall not 
be prohibited from conveying combustion 
air, provided that not more than- one 
fireblock is removed. 

(2) Ducts shall terminate in an unobstructed space, 
allowing free movement of combustion air to the 
appliances. [NFPA 54:9.3.8.2] 

(3) Ducts shall serve a single space. [NFPA 
54:9.3.8.3] 

(4) Ducts shall not service both upper and lower 
combustion air openings where both such 
openings are used. The separation between ducts 
serving upper and lower combustion-air openings 
shall be maintained to the source of combustion 
air. [NFPA 54:9.3.8.4] 



(5) Ducts terminating in attics shall not be screened. 
[NFPA 54:9.3.8.5] 

(6) Intakes for combustion-air ducts located exterior 
to the building shall have the lowest side of the 
combustion-air intake operiings located at least 
twelve (12) inches vertically from the adjoining 
grade level. [NFPA 54:9.3.8.8] 

(7) Horizontal upper combustion-air ducts shall not 
slope downward toward the source of 
combustion air. [NFPA 54:9.3.8.6] 

(8) The remaining space surrounding a chimney liner, 
gas vent, special gas vent, or, plastic piping 
installed within a masonry chimney flue metal or 
factory-built chimney shall not be used to supply 
combustion air imless it is listed and shown in the 
manufacturer's installation instructions. [NFPA 
54:9.3.8.7] 

701.11 Dampers Prohibited. Combustion-air ducts or 
plenums shall not be installed so as to require 
openings in or penetrations through construction 
where fire dampers are required. Manually operated 
dampers shall not be installed in combustion-air 
openings. With prior approval, power-actuated 
movable louvers admitting combustion air may be 
used and, if installed, shall be electrically interlocked 
with the main burner fuel-supply valve so as to 
prevent fuel delivery unless the louvers are in the fully 
open position. 



Chimney or gas vent 




Opening 



Opening 



XZI 



I I 



rrc 



III 



I I 



FIGURE 7-1 All Combustion Air from Indoor 
Spaces Through Indoor Combustion Air 
Openings. [NFPA 54: A8.3.2.3(1)] | 



109 



Figure 7-2 - Figure 7-5 



2007 CALIFORNIA MECHANICAL CODE 



-Chimney or gas vent 



Alternate 
air inlet— 



Ventilation louvers 
(each end of attic) 




Furnace 



Water 
heater 



xrr 



^ 



• Outlet air 



/' 



Inlet air 



I, , IIJIJIII I ' I I I ' . I 



-r-i 



■ I I " I 



m 



■ Ventilation louvers for - 
unheated crawl space 

FIGURE 7-2 All Combustion Air from Outdoors- 
Inlet Air from Ventilated Crawl Space and Outlet 
I Air to Ventilated Attic. [NFPA54: A.8.3.3.(1) (A)] 



- Chimney or gas vent 




m 



FIGURE 7-4 All Combustion Air from Outdoors 
Through Horizontal Ducts. [NFPA 54: A.8.3.3.1 (2)] | 



Chimney or gas vent 



Ventilation louvers 
(each end of attic) 




Chimney or gas vent 



Inlet air duct 
[ends 1ft (300 mm) 
above floor] 




I* — Opening 

Alternate 
opening 
location 



FIGURE 7-3 All Combustion Air from Outdoors FIGURE 7-5 All Combustion Air from Outdoors 
I Through Ventilated Attic. [NFPA 54: A.8.3.3.1 {1)(b)] Through Single Combustion Air Opening. [NFPA 

54:A.8.3.3.2] 



110 



CHAPTERS 

CHIMNEYS AND VENTS 
Note: Portions of this chapter have been reproduced in their entirety from NFPA 54-2006 (ANSI Z223.1). 



801.0 Scope. 

The requirements of this chapter shall govern the 
venting of fuel-burning appliances. 

801.1 Venting of Gas Appliances. Low-heat 
gas appliances shall be vented in accordance 
with this chapter. Other gas appliances shall be 
vented in accordance with NFPA 211 or other 
applicable standards. 

801.2 Appliances Fueled by Other Fuels. 

Appliances fueled by fuels other than gas shall be 
vented in accordance with NFPA 211 and the 
appliance manufacturer's instructions. 

802.0 General. 

802.1 This section recognizes that the choice of 
venting materials and the methods of installation 
of venting systems are dependent on the operating 
characteristics of the gas utilization equipment. The 
operating characteristics of vented gas utilization 
equipment can be categorized with respect to (1) 
positive or negative pressure within the venting 
system, and (2) whether or not the equipment 
generates flue or vent gases that can condense in 
the venting system. See Section 224.0 for the 
definition of these vented appliance categories. 
[NFPA 54:12.2] 

802.2 Specification for Venting. 

802.2.1 Connection to Venting Systems. 

Except as permitted in Section 802.2.2 through 
802.2.6, all gas utilization equipment shall be 
connected to venting systems. [NFPA 54:12.3.1] 

802.2.2 Equipment Not Required to Be 
Vented. The following equipment shall not be 
required to be vented [NFPA 54:12.3.2]: 

802.2.2.1 Listed ranges. [NFPA 54:12.3.2(1)] 

802.2.2.2 Built-in domestic cooking units 
listed and marked for optional venting. 
[NFPA 54:12.3.2(2)] 

802.2.2.3 Listed hot plates and listed 
laundry stoves. [NFPA 54:12.3.2(3)] 

802.2.2.4 Listed Type 1 clothes dryers 
exhausted in accordance with Section 

,, ,, 504.3.2. [NFPA 54:12.3.2(4)] 

802.2.2.5 A single listed booster-type 



(automatic instantaneous) water heater, 
when designed and used solely for the 
sanitizing rinse requirements of a 
dishwashing machine, provided that the 
equipment is installed with the draft hood 
in place and unaltered, if a draft hood is 
required, in a commercial kitchen having a 
mechanical exhaust system; where installed 
in this inanner, the draft hood outlet shall 
hot be less than thirty-six (36) inches (910 
mm) vertically and six (6) inches (150 mm) 
horizontally from any surface other than 
the equipment. [NFPA 54:12.3.2(5)] 

802.2.2.6 Listed refrigerators. [NFPA 
54:12.3.2(6)] ■ 

802.2.2.7 Counter appliances. [NFPA 
54:12.3.2(7)] 

802.2.2.8 Room heaters listed for unvented 
use (see Sections 924J and 924.2). [NFPA 
54:12.3.2(8)] 

802.2.2.9 Direct gas-fired makeup air heaters. 
[NFPA 54:12.3.2(9)] 

802.2.2.10 Other equipment listed for 
unvented use and not provided with flue 
collars. [NFPA 54:12.3.2(10)] 

802.2.2.11 Specialized equipment of 
limited input such as laboratory burners 
or gas lights. [NFPA 54:12.3.2(11)] 

Where any or all of this equipment in Sections 
802.2.2.5 through 802.2.2.11 is installed so the 
aggregate input rating exceeds 20 Btu/h/ft.^ (207 
W/m^) of room or space in which it is installed, 
one or more shall be provided with venting 
systems or other approved means for removing 
the vent gases to the outside atmosphere so the 
aggregate input rating of the remaining 
unvented equipment does not exceed 20 
Btu/h/ff (207 W/m^). Where the calculation 
includes the volume of an adjacent room or 
space, the room or space in which the equipment 
is installed shall be directly connected to the 
adjacent rpom or space by a doorway, archway, 
or other opening of comparable size that cannot 
be closed. [NFPA 54:12.3.1] 

802.2.3 Ventilating Hoods. Ventilating hoods 
and exhaust systems shall be permitted to be 



I 



111 



802.2 - 802.4 



2007 CALIFORNIA MECHANICAL CODE 



used to vent gas utilization equipment installed 
in commercial applications (see Section 802.3.5) 
and to vent industrial equipment, particularly 
where the process itself requires fume disposal. 
[NFPA 54:12.3.3] 

802.2.4 Well-Ventilated Spaces. The operation 
of industrial gas utilization equipment such that 
its flue gases are discharged directly into a large 
and well-ventilated space shall be permitted. 
[NFPA 54:12.3.4] 

802.2.5 Direct-Vent Equipment. Listed direct- 
vent gas utilization equipment shall be 
considered properly vented where installed in 
accordance with the terms of its listing, the 
manufacturers' instructions, and Section 802.8.3. 

802.2.6 Equipment with Integral Vents. Gas 

utilization equipment incorporating integral 
venting means shall be considered properly 
vented where installed in accordance with its 
listing, the manufacturers' instructions, and 
Sections 802.8.1 and 802.8.2. [NFPA 54:12.3.6] 

802.3 Design and Construction. 

802.3.1 Minimum Safe Performance. A venting 
system shall be designed and constructed so as to 
develop a positive flow adequate to remove flue 
or vent gases to the outside atmosphere. [NFPA 
54:12.1] 

802.3.2 Equipment Draft Requirements. A 

venting system shall satisfy the draft 
requirements of the equipment in accordance 
with the manufacturer's instructions. [NFPA 
54:12.4.1] 

802.3.3 Design and Construction. Gas utilization 
equipment required to be vented shall be 
connected to a venting system designed and 
installed in accordance with the provisions of 
Sections 802.4 through 802.15. [NFPA 54:12.4.2] 

802.3.4 IVIechanical Draft Systems. 

802.3.4.1 Mechanical draft systems shall be 
listed and shall be installed in accordance 
with the terms of their listing and both the 
appliance and the mechanical draft system 
manufacturers' instructions. [NFPA 54:12.4.3.1] 

802.3.4.2 Gas utilization equipment requiring 
venting shall be permitted to be vented by 
means of mechaoical draft systems of either 
forced or induced draft design. [NFPA 
54:12.4.3.2] 

Exception: Incinerators. 

802.3.4.3 Forced draft systems and all 
portions of induced draft systems under 
positive pressure during operation shall be 



designed and installed so as to prevent 
leakage of flue or vent gases into a building. 
[NFPA 54:12.4.3.3] 

802.3.4.4 Vent connectors serving eqtiipment 
vented by natural draft shall not be connected 
into any portion of mechanical draft systems 
operating under positive pressure. [NFPA 
54:12.4.3.4] 

802.3.4.5 Where a mechanical draft system 
is employed, provision shall be made to 
prevent the flow of gas to the main burners 
when the draft system is not performing so 
as to satisfy the operating requirements of 
the equipment for safe performance. [NFPA 
54:12.4.3.5] 

802.3.4.6 The exit terminals of mecharucal 
draft systems shall be not less than seven (7) 
feet (2.1 m) above grade where located 
adjacent to public walkways and shall be 
located as specified in Sections 802.8.1 and 
802.8.2. [NFPA 54:12.4.3.6] 

802.3.5 Ventilating Hoods and Exhaust Systems. 

802.3.5.1 Ventilating hoods and exhaust 
systems shall be permitted to be used to 
vent gas utilization equipment installed in 
conmnercial applications. [NFPA 54:12.4.4.1] 

802.3.5.2 Where automatically operated gas 
utilization equipment is vented through a 
ventilating hood or exhaust system 
equipped with a damper or with a power 
means of exhaust, provisions shall be made 
to allow the flow of gas to the main burners 
only when the damper is open to a position 
to properly vent the equipment and when 
the power means of exhaust is in operation. 
[NFPA 54:12.4.4.2] 

802.3.6 Circulating Air Ducts and Furnace 
Plenums. No portion of a venting system shall 
extend into or pass through any circulating air 
duct or furnace plenum. [NFPA 54:12.4.5.1] 

802.4 Type of Venting System to Be Used. 

802.4.1 The type of venting system to be used 
shall be in accordance with Table 8-1. [NFPA 
54:12.5.1] 

802.4.2 Plastic Piping. Plastic piping used for 
venting equipment listed for use with such 
venting materials shall be approved. [NFPA 
54:12.5.2] 

802.4.3 Special Gas Vent. A special gas vent 
shall be listed and installed in accordance with 
the terms of the special gas vent listing and the 
manufacturers' instructions. [NFPA 54:12.5.3] 



I 



112 



CHIMNEYS AND VENTS 



802.5 - Table 8-1 



802.5 Masonry, Metal, and Factory-Built Chimneys. 
802.5.1 Listing or Construction. 

802.5.1.1 Factory-built chimneys shall be 
installed in accordance with their listing and 
the manufacturers' instructions. Factory- 
built chimneys used to vent appliances that 
operate at positive vent, pressure shall be 
listed for such application. [NFPA 
54:12.6.1.1] 

802.5.1.2 Metal chimneys shall be built and 
installed in accordance with NFPA 211, 
Standard for Chimneys, Fireplaces, Vents, 
and Solid-Fuel-Burning Appliances. [NFPA 
54:12.6.1.2] 

802.5.1.3 Masonry chimneys shall be built 
and installed in accordance with NFPA 211, 
Standard for Chimneys, Fireplaces, Vents, 
and Solid-Fuel-Burning Appliances, and 
lined with an approved clay flue lining, a 
listed chimney lining system, or other 
approved material that will resist corrosion, 
erosion, softening, or cracking from vent 
gases at temperatures up to 1,800°F (982°C). 
[NFPA 54:12.6.1.3] 

Exception: Masonry chinnney flues lined 
with a chinmey lining system specifically 
listed for use with listed gas appliances 
with draft hoods. Category I appliances, 
and other gas appliances listed for use 
with Type B vents shall be permitted. 
The liner shall be installed in accordance 
with the Hner manufacturer's instructions 
and the terms of the listing. A permanent 
identifying label shall be attached at the 
point where the connection is to be made 
to the liner. The label shall read: "This 
chimney liner is for appliances that burn 
gas only. Do not connect to solid or Uqmd- 
fuel-burning appliances or incinerators." 
802.5.2 Termination. 

802.5.2.1 A chimney for residential-type or 
low-heat gas utilization equipment shall 
extend at least three (3) feet (0.9 m) above the 
highest point where it passes through a roof 
of a building and at least two (2) feet (0.6 m) 
higher than any portion of a building within 
a horizontal distance of ten (10) ieet (3.0 m). 
(See Figure 8-1.) [NFPA 54:12.6.2.1] 



TABLE 8-1 
Type of Venting System to Be Used 



Gas Utilization Equipment 

Listed Category I equipment 
Listed equipment equipped 

with draft hood 
Equipment listed for use with 

Type B gas vent 



Type of Venting System 

Type B gas vent (802.6) 

Chimney (802.5) 

Single-waU metal pipe 

(802.7) 

Listed chinmey lining 
system for gas venting 
(802.5.1.3) 

Special gas vent listed 
for this eqmpment 
(802.4.3) 



Listed vented wall furnaces 



Type B-W gas vent 
(802.6, 928.0) 



Category 11 equipment 
Category in equipment 
Category IV equipment 



~hs speatied. or tumished 

bymanujfecturers of listed 

equipment (802.4.2, 
802.4.3) 



incinerators, outdoors 



"Bingie-wall metal pipe 
(802.7, 802.7.3.3) 



Incinerators, indoors Chimney (802.5) 

Equipment that can be Type L vent (802.6) or 

converted to use of solid fuel chimney (802.5) 



Unlisted combination gas- and 
oil-burning equipment 

Combination gas- and solid-fuel- 
burning equipment 

Equipment listed for use with 
chimneys only 

Unlisted equipment 

Listed combination gas- and 
oil-burning equipment 



Decorative appliance in vented Chimney [907.2(3)] 
fireplace 



Gas-fired toilets 



Single-waU metal pipe 
(802.7, 926.3) 



Direct-vent equipment 



See 802.2.5 



Equipment with integral vent See 802.2.6 



[NFPA 54: Table 12.5.1] 



113 



Figure 8-1 - 802.5 



2007 CALIFORNIA MECHANICAL CODE 



-10 ft (3.0 m) 



2 ft (0.6 m) 
minimum — 



3 ft (0.9 m) 
minimum 

i_ 




(a) Termination 10 ft (3.0 m) or Less from Ridge, Wall, or Parapet 



More than 
- 10 ft (3.0 m)- 



Wall or 
parapet 



^ 



&m^:mm'-ammm\ 



-4^ 



Note: No height 
above parapet 
required whan 
distance from walls 
or parapet is more 
than 10 ft (3.0 m). 



3 ft (0.9 m) 
minimum 



Chimney 



Ridge 



It/lore than 
■ 10 ft (3,0 m) - 

♦-10 ft (3.0 m)* 
2 ft (0.6 m) ^ 



minimum 



3 ft (0.9 m) 
minimum 




l-<eight above any 
roofsurface within 
10 ft (3.0 m) horizontally 



Chimney 



(b) Termination Mote Than 10 ft (3.0 m) from Ridge, Wall, or Parapet 



FIGURE 8-1 Typical Termination Locations for 
Chimneys and Single-Wall Metal Pipes Serving 
Residential-Type and Low-Heat Equipment. 
[NFPA 54: Figure 12.6.2.1] 



802.5.2.2 A chimney for medium-heat 
eqtdpment shall extend at least ten (10) feet 
(3.0 m) higher than any portion of any 
btiilding within twenty-five (25) feet (7.6 m). 
[NPPA 54:12.6.2.2] 

802.5.2.3 A chimney shall extend at least 
five (5) feet (1.5 m) above the highest 
connected equipment draft hood outlet or 
flue coUar. [NFPA 54:12.6.2.3] 

802.5.2.4 Decorative shrouds shall not be 
installed at the termination of factory-built 
chimneys except where such shrouds are 
listed and labeled for use with the specific 
factory-built chimney system and are 
installed in accordance with manufacturers' 
installation instructions. [NFPA 54:12.6.2.4] 

802.5.3 Size of Chimneys. The effective area of 
a chimney venting system serving listed gas 
appliances with draft hoods. Category I 
appliances, and other appliances listed for use 
with Type B vents shall be in accordance with 
one of the following methods [NFPA 54:12.6.3.1]: 

(1) Section 803.0. [NFPA 54:12.6.3.1(1)] 

(2) For sizing an individual chimney venting 
system for a single appliance with a draft 
hood, the effective areas of the vent 
connector and chimney flue shall be not less 
than the area of the appliance flue collar or 
draft hood outlet or greater than seven times 
the draft hood outlet area. [NFPA 
54:12.6.3.1(2)] 

(3) For sizing a chimney venting system 
connected to two appliances with draft 
hoods, the effective area of the chimney flue 
shall be not less than the area of the larger 
draft hood outlet plus 50 percent of the area 
of the smaller draft hood outlet, or greater 
than seven times the smallest draft hood 
outlet area. [NFPA 54:12.6.3.1(3)] 

(4) Other approved engineering methods. 
[NFPA 54:12.6.3.1(5)] 

(5) Chimney venting systems using mechanical 
draft shall be sized in accordance with 
approved engineering methods. [NFPA 
54:12.6.3.1(4)] 

802.5.4.1 Where an incinerator is vented by 
a chimney serving other gas utilization 
equipment, the gas input to the incinerator 
shall not be included in calculating chimney 
size, provided the chimney flue diameter is 
not less than one (1) inch (25 mm) larger in 



114 



CHIMNEYS AND VENTS 



802.5 - 802.6 



equivalent diameter than the diameter of the 
incinerator flue outlet. [NFPA 54:12.6.3.2] 

802.5.4 Inspection of Chimneys. 

802.5.4.1 Before replacing an existing 
appliance or connecting a vent connector to 
a chimney, the chimney passageway shall be 
examined to ascertain that it is clear and free 
of obstructions and shall be cleaned if 
previously used for venting solid- or liquid- 
fuel-burning appliances or fireplaces. 
[NFPA 54:12.6.4.1] 

802.5.4.2 Chimneys shall be lined in 
accordance with NFPA 211, Standard for 
Chimneys, Fireplaces, Vents and Solid Fuel- 
Burning Appliances. [NFPA 54:12.6.4.2] 

802.5.4.3 Cleanouts shall be examined to 
determine they will remain tightly closed 
when not in use. [NFPA 54:12.6.4.3] 

802.5.4.4 When inspection reveals that an 
existing chimney is not safe for the intended 
application, it shall be repaired, rebuilt, 
lined, relined, or replaced with a vent or 
chimney to conform to NFPA 211, Standard 
for Chimneys, Fireplaces, Vents, and Solid- 
Fuel-Burning Appliances, and shall be 
suitable for the equipment to be attached. 
[NFPA 54:12.6.4.4] 

802.5.5 Chimney Serving Equipment Burning 
Other Fuels. 

802.5.5.1 Gas utilization equipment shall not 
be connected to a chimney flue serving a 
separate appliance designed to bum solid fuel. 

802.5.5.2 Where one chimney serves gas 
utilization equipment and equipment 
burning liquid fuel, the equipment shall be 
connected through separate openings or 
shall be connected through a single opening 
where joined by a suitable fitting located as 
close as practical to the chinmey. Where two 
or more openings are provided into one 
chimney flue, they shall be at different 
levels. Where the gas utilization equipment 
is automatically controlled, it shall be 
equipped with a safety shutoff device. 

802.5.5.3 A listed combination gas and soUd- 
fuel-buming appHance connected to a single 
chimney flue shall be eqtiipped with a manual 
reset device to shut off gas to the main burner 
in the event of sustained backdraft or flue gas 
spillage. The chimney flue shall be sized to 
properly vent the appliance. 



802.5.5.4 A single chimney flue serving a Usted 
combination gas and oil-burning appliance 
shall be sized to properly vent the appliance. 

802.5.6 Support of Chimneys. All portions of 
chimneys shall be supported for the design and 
weight of the materials employed. Listed 
factory-built chimneys shall be supported and 
spaced in accordance with their listings and the 
manufacturers' instructions. 

802.5.7 Cleanouts. Where a chimney that 
formerly carried flue products from liquid-or 
solid-fuel-burning appliances is used with an 
appliance using fuel gas, an accessible cleanout 
shall be provided. The cleanout shall have a 
tight-fitting cover and be installed so its upper 
edge is at least six (6) inches (150 mm) below the 
lower edge of the lowest chimney inlet opening. 

802.5.8 Space Surrounding Lining or Vent. 

The remaining space surrounding a chimney 
liner, gas vent, special gas vent, or plastic piping 
installed within a masonry chimney flue shall 
not be used to vent another appliance. 

Exception: The insertion of another liner or 
vent within the chimney as provided in this 
code and the liner or vent manufacturer's 
instructions. 

The remaining space surounding a chimney 
liner, gas vent, special gas vent, or plastic piping 
installed within a masonry, metal or factory- 
built chimney flue shall not be used to supply 
combustion air. 

Exception: Direct vent gas-fired appliances 
designed for installation in a solid-fuel- 
burning fireplace where installed in 
accordance with the listing and the 
manufacturer's instruction. [NFPA 54:10.5] 

802.6 Gas Vents. 

802.6.1 A gas vent passing through a roof shall 
extend through the entire roof flashing, roof 
jack, or roof thimble and be terminated with a 
listed termination cap. 

802.6.1.1 Type B or Type L vents shall 
extend in a generally vertical direction with 
offsets not exceeding 45 degrees, except that 
a vent system having not more than one 60 
degree offset shall be permitted. Any angle 
greater than 45 degrees from the vertical is 
considered horizontal. The total horizontal 
distance of a vent plus the horizontal vent 
connector serving draft hood equipped 
appliances shall not be greater than 75 
percent of the vertical height of the vent. 



115 



802.6 



2007 CALIFORNIA MECHANICAL CODE 



Exception: Systems designed and sized as 
provided in Section 803.0 or in accordance 
with other approved engineering methods. 

Vents serving Category I fan-assisted 
appliances shall be installed in accordance 
with the appliance manufacturer's instruc- 
tions and Section 803.0 or other approved 
engineering methods. 

802.6.2 A gas vent shall terminate in accordance 
with one of the following: 

(1) Above the roof siirface with a Usted cap 
or listed roof assembly. Gas vents 
twelve (12) inches (300 mm) in size or 
smaller with listed caps shall be permitted 
to be terminated in accordance with 
Figure 8-2, provided they are at least 
eight (8) feet (2.4 m) from a vertical wall 
or similar obstruction. All other gas 
vents shall terminate not less than two 
(2) feet (0.6 m) above the highest point 
where they pass through the roof and at 
least two (2) feet (0.6 m) higher than any 
portion of a building within ten (10) feet 
(3.1 m). 

(2) Industrial gas utilization equipment as 
provided in Section 802.2.4. 

Usted Lowe st cli,scharge opening^ 
cap """1 1. . I 

Listed gas 
vent * 




lsx'12 



H (minimum) - 
Minimum height from roof 
to lowest discharge opening 



Roof pitch 


H (minimum) ft 


m 


Flat to 6/12 


1.0 


0.30 


6/12 to 7/12 


1.25 


0.38 


Over 7/12 to 8/12 


1.5 


0.46 


Over 8/1 2 to 9/1 2 


2.0 


0.61 


Over 9/12 to 10/12 


2.5 


0.76 


Over 10/12 to 11/12 


3.25 


0.99 


Over 11/12 to 12/12 


4.0 


1.22 


Over 12/12 to 14/12 


5.0 


1.52 


Over 14/12 to 16/12 


6.0 


1.83 


Over 16/12 to 18/12 


7.0 


2.13 


Over 18/12 to 20/12 


7.5 


2.27 


Over 20/12 to 21/12 


8.0 


2.44 



FIGURE 8-2 Gas Vent Termination Locations for 
Listed Caps 12 in. (300 mm) or Less in Size at 
Least 8 ft. (2.4 m) from a Vertical Wall. [NFPA 54: 
Figure 10.6.2] 



(3) Direct-vent systems as provided in 
Section 802.2.5. 

(4) Equipment with integral vents as 
provided in Section 802.2.6. 

(5) Mechanical draft systems as provided in 
Section 802.3.4. 

(6) Ventilating hoods and exhaust systems 
as provided in Section 802.3.5. 

802.6.2.1 A Type B or a Type L gas vent 
shall terminate at least five (5) feet (1.5 m) in 
vertical height above the highest connected 
equipment draft hood or flue collar. 

802.6.2.2 A Type BW gas vent shall 
terminate at least twelve (12) feet (3.7 m) in 
vertical height above the bottom of the wall 
furnace. 

802.6.2.3 A gas vent extending through an 
exterior wall shall not terminate adjacent to 
the wall or below eaves or parapets, except 
as provided in Sections 802.2.5 and 802.3.4. 

802.6.2.4 Decorative shrouds shall not be 
installed at the termination of gas vents 
except where such shrouds are listed for use 
with the specific gas venting system and are 
installed in accordance with manufacturers' 
installation instructions. 

802.6.2.5 All gas vents shall extend through 
the roof flashing, roof jack, or roof thimble 
and terminate with a Usted cap or listed roof 
assembly. [NFPA 54:12.7.2 (6)] 

802.6.2.6 A gas vent shall terminate at least 
three (3) feet (0.9 m) above a forced air inlet 
located within ten (10) feet (3.0 m). [NFPA 
54:12.7.2 (7)] 

802.6.3 Size of Gas Vents. Venting systems 
shall be sized and constructed in accordance 
with Section 803.0 or other approved engineering 
methods and the gas vent and gas equipment 
manufacturers' instructions. 

802.6.3.1 Category I Appliances. The sizing 
of natural draft venting systems serving one 
or more listed appliances equipped with a 
draft hood or appliances listed for use with 
Type B gas vent, installed in a single story of 
a building, shall be in accordance with one of 
the following methods. 

(1) The provisions of Section 803.0. 

(2) Vents serving fan-assisted combustion 
system appliances, or combinations of 
fan-assisted combustion system and 
draft hood-equipped appliances shall be 



116 



CHIMNEYS AND VENTS 



802.6 



i 



^ 



sized in accordance with Section 803.0 
or other approved engineering methods. 

(3) For sizing an individual gas vent for a 
single, draft hood-equipped appliance, 
the effective area of the vent coimector 
and the gas vent shall be not less than 
the area of the appliance draft hood 
outlet or greater than seven times the 
draft hood outlet area. 

(4) For sizing a gas vent connected to two 
appliances, with draft hoods, the 
effective area of the vent shall be not 
less than the area of the larger draft 
hood outlet plus 50 percent of the area 
of the smaller draft hood outlet or 
greater than seven times the smaller 
draft hood outlet area. 

(5) Approved engineering practices. 

802.6.3.2 Category II, Category III, and 
Category IV Appliances. The sizing of gas 
vents for Category II, Category III, and 
Category IV gas utilization equipment shall 
be in accordance with the equipment 
manufacturers' instructions. 

802.6.3.3 Sizing. Chimney venting systems 
using mechanical draft shall be sized in 
accordance with approved engineering 
methods. 



TVV 



Gas furnace - 



-i Outlet plenum J ^ 



U^ 




Type B gas vents 



-Air grilles In 
outside walls 



Outside balcony 
or service area 



n. 



-Louvered door could 
be used in lieu ot 
outside wall grilles 



JV- 



FIGURE 8-3 Plan View of Practical Separation 
Method for Multistory Gas Venting. [NFPA 54: 
Figure 810.6.4] 



802.6.4 Gas Vents Serving Equipment on 
More Than One Floor. A common gas vent shall 
be permitted in multistory installations to vent 
Category I gas utilization equipment located on 
more than one floor level, provided the venting 
system is designed and installed in accordance 
with approved engineering methods. For the 
purpose of this section, crawl spaces, basements, 
and attics shall be considered as floor levels. 

All gas utilization equipment connected to 
the common vent shall be located in rooms 
separated from habitable space. Each of these 
rooms shall have provisions for an adequate 
supply of combustion, ventilation, and dilution 
air that is not supplied from habitable space. 
(See Figure 8-3.) 

The size of the connectors and common 
segments of multistory venting systems for gas 
utilization equipment listed for use with Tj^e B 
double-wall gas vent shaU be in accordance with 
Table 8-10, provided: 

(1) The available total height (H) for each 
segment of a multistory venting system is 
the vertical distance between the level of the 
highest draft hood outlet or flue collar on 
that floor and the centerline of the next 
highest interconnection tee. (See Figure 8-4.) 

(2) The size of the connector for a segment is 
determined from its gas utilization 
equipment heat input and available 
coimector rise, and shall not be smaller than 
the draft hood outlet or flue collar size. 

(3) The size of the common vertical vent 
segment, arid of the interconnection tee at 
the base of that segment, shall be based on 
the total gas utilization equipment heat 
input entering that segment arid its available 
total height. 

802.6.5 Support of Gas Vents. Gas vents shall 
be supported and spaced in accordance with 
their listings and the manufacturers' instructions. 

802.6.6 Marking. In those localities where solid 
and liquid fuels are used extensively, gas vents 
shall be permanently identified by a label 
attached to the wall or ceiling at a point where 
the vent coimector enters the gas vent. The label 
shall read: "This gas vent is for appliances that 
burn gas. Do not connect to solid or liquid-fuel- 
burning appliances or incinerators." The 
Authority Having Jurisdiction shall determine 
whether its area constitutes such a locality. 
[NFPA 54:10.6] 1 



117 



Table 8-2 - 802.7 



2007 CALIFORNIA MECHANICAL CODE 



TABLE 8-2 
Clearance for Connectors 



Minimum Distance from Combustible Material 



Equipment 



Listed Type B 
Gas Vent Material 



Listed Type L 
Vent Material 



Single-Wall 
Metal Pipe 



Factory-Built 
Ciiimney Sections 



Listed equipment with 
draft hoods and eqvdp- 
ment listed for use with 
T)rpe B gas vents 



As listed 



As listed 



Residential boilers and 
furnaces with listed gas 
conversion burner and 
with draft hood 


6 in. 


6 in. 


Residential appliances 
listed for use with Type 
L vents 


Not permitted 


As listed 


Residential incinerators 


Not permitted 


9 in. 


Listed gas-fired toilets 


Not permitted 


As listed 


Unlisted residential 
appliances with draft 
hood 


Not permitted 


6 in. 


Residential and low-heat 
equipment other than 
those above 


Not permitted 


9ia. 


Medium-heat equipment 


Not permitted 


Not permitted 



6 in. 
9 in. 

9 in. 

18 in. 
As Usted 
9 in. 

18 in. 

36 in. 



As listed 
As listed 

As listed 

As listed 
As Usted 
As listed 

As listed 

As listed 



For SI units, 1 in.= 25.4 mm. 

Note: These clearances shaU apply unless the listing of an appliance or connector specifies clearances, in which case the listed 
I clearances shall apply. [NFPA 54: Table 10.7.4.4] 



802.7 Single-Wall Metal Pipe. 

802.7.1 Construction. Single-wall metal pipe 
shaU be constructed of galvanized sheet steel not 
less than 0.0304 inch (0.7 inm) thick or of other 
approved, noncombustible, corrosion-resistant 
material. 

802.7.2 Cold Climate. Uninsulated single-wall 
metal pipe shall not be used outdoors in cold 
climates for venting gas utilization equipment 
in regions where the 99 percent winter design 
temperature is below 32 degrees Fahrenheit. 
[NFPA 54:12.8.2] 

802.7.3 Termination. The termination of single- 
wall metal pipe shall comply with the following 
requirements: 

802.7.3.1 Single-wall metal pipe shall 
terminate at least five (5) feet (1.5 m) in 
vertical height above the highest connected 
equipment draft hood outlet or flue collar. 

802.7.3.2 Single-wall metal pipe shall 
extend at least two (2) feet (0.6 m) above the 



highest point where it passes through a roof 
of a building and at least two (2) feet (0.6 m) 
higher than any portion of a building within 
a horizontal distance of ten (10) feet (3.1 m). 
(See Figure 8-1.) 

802.7.3.3 An approved cap or roof assembly 
shall be attached to the terminus of a single- 
wall metal pipe. (Also see Section 802.7.4.3.) 

802.7.4 Installation with Equipment Permitted 
by Section 802.4.1. 

802.7.4.1 Single-wall metal pipe shall be 
used only for runs directly from the space 
in which the gas utilization equipment is 
located through the roof or exterior wall to 
the outer air. A pipe passing through a 
roof shall extend without interruption 
through the roof flashing, roof jacket, or 
roof thimble. 

802.7.4.2 Single-wall metal pipe shall not 
originate in any unoccupied attic or 
concealed space and shall not pass through 



118 



CHIMNEYS AND VENTS 



802.7 - 802.9 



any attic, inside wall, concealed space, or 
floor. For the installation of a single-wall 
metal pipe through an exterior combustible 
wall see Section 802.10.14.2. 

802.7.4.3 Single-wall metal pipe used for 
venting an incinerator shall be exposed and 
readily examinable for its full length and 
shall have suitable clearances maintained. 

802.7.4.4 Minimum clearances from single- 
wall metal pipe to combustible material 
shall be in accordance with Table 8-2. 
Reduced clearances from single-wall metal 
pipe to combustible material shall be as 
specified for vent connectors in Table 5-3. 

802.7.4.5 Where a single-wall metal pipe 
passes through a roof constructed of 
combustible material, a noncombustible, 
nonventilating thimble shall be used at the 
point of passage. The thimble shall extend at 
least eighteen (18) inches (460 mm) above and 
six (6) inches (150 mm) below the roof, with 
the annular space open at the bottom and 
closed only at the top. The thimble shall be 
sized in accordance with Section 802.10.14.2. 

802.7.5 Size of Single-Wall Metal Pipe. Single- 
wall metal piping shall comply with the 
following requirements: 

802.7.5.1 A venting system of a single-wall 
metal pipe shall be sized in accordance with 
one of the following methods and the gas 
equipment manufacturer's instructions: 

(1) For a draft hood-equipped appliance, in 
accordance with Section 803.0. 

(2) For a venting system for a single 
appliance with a draft hood, the areas of 
the cormector and the pipe each shall 
not be less than the area of the appliance 
flue collar or draft hood outlet, whichever 
is smaller. The vent area shall not be 
greater than seven times the draft hood 
outlet area. 

(3) Other approved engineering methods. 

802.7.5.2 Where a single-wall metal pipe is 
used and has a shape other than roimd, it shall 
have an equivalent effective area equal to the 
effective area of the round pipe for which it is 
substituted, and the minimum internal 
dimension of the pipe shall be two (2) inches 
(50 mm). 

802.7.5.3 The vent cap or a roof assembly 
shall have a venting capacity not less than 
that of the pipe to which it is attached. 



802.7.6 Support of Single-Wall Metal Pipe. All 

portions of single-wall metal pipe shall be 
supported for the design and weight of the 
material employed. 

802.7.7 Marking. Single-wall metal pipe shall 
comply with the marking provisions of Section 
802.6.6. [NFPA 54:10.7] 

802.8 Through-the-Wall Vent Termination. 

802.8.1 A mechanical draft venting system shall 
terminate at least three (3) feet (0.9 m) above any 
forced air inlet located within ten (10) feet (3.1 m). 

Exception 1: This provision shall not apply 
to the combustion-air intake of a direct-vent 
appliance. 

Exception 2: This provision shall not apply 
to the separation of the integral outdoor-air 
iiUet and flue gas discharge of listed outdoor 
appliances. 

802.8.2 A mechanical draft venting system of 
other than direct-vent type shall terminate at 
least four (4) feet (1.2 m) below, four (4) feet (1.2 
m) horizontally from, or one (1) feet (300 mm) 
above any door, operable window, or gravity air 
inlet into any building. The bottom of the vent 
terminal shall be located at least twelve (12) 
inches (300 mm) above grade. 

802.8.3 The vent terminal of a direct-vent 
appliance with an input of 10,000 Btu/h (3 kW) 
or less shaU be located at least six (6) inches (150 
mm) from any air operiing into a building, and 
such an appliance with an input over 10,000 
Btu/h (3 kW) but not over 50,000 Btu/h (14.7 
kW) shall be installed with a nine (9) inches (230 
mm) vent termination clearance, and an 
appUance with an input over 50,000 Btu/h (14.7 
kW) shall have at least a twelve (12) inches (300 
mm) vent termination clearance. The bottom of 
the vent terminal and the air intake shall be 
located at least twelve (12) inches (300 mm) 
above grade. 

802.8.4 Through-the-wall vents for Category 11 
and Category IV appliances and noncategorized 
condensing appliances shall not terminate over 
public walkways or over an area where 
condensate or vapor could create a nuisance or 
hazard or could be detrimental to the operation 
of regulators, relief valves, or other equipment. 
Where local experience indicates that 
condensate is a problem with Category I and 
Category III appliances, this provision shall 
also apply. [NFPA 54:10.8] 

802.9 Condensation Drain. 

802.9.1 Provision shall be made to collect and 



119 



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2007 CALIFORNIA MECHANICAL CODE 



dispose of condensate from venting systems 
serving Category II and Category IV gas 
utilization equipment and noncategorized 
condensing appliances in accordance with 
Section 802.8.4. 

802.9.2 Where local experience indicates that 
condensation is a problem, provision shall be 
made to drain off and dispose of condensate 
from venting systems serving Category I and 
Category III gas utilization equipment in 
accordance with Section 802.8.4. [NFPA 54:10.9] 

802.10 Vent Connectors for Category I Gas 
Utilization Equipment. 

802.10.1 Where Required. A vent cormector 
shall be used to connect gas utilization 
equipment to a gas vent, chimney, or single- 
wall metal pipe, except where the gas vent, 
chimney, or single-wall metal pipe is directly 
connected to the equipment. 

802.10.2 IViaterials. 

802.10.2.1 A vent connector shall be made 
of noncombustible, corrosion-resistant 
material capable of withstanding the vent 
gas temperature produced by the gas 
utilization equipment and of sufficient 
thickness to withstand physical damage. 

802.10.2.2 Where the vent connector used for 
gas utilization equipment having a draft hood 
or a Category I appliance is located in or 
passes through an imconditioned area, that 
portion of the vent cormector shall be listed 
Type B, listed Type L, or listed vent material 
having equivalent insulation qualities. 

Exception: Single-wall metal pipe 
located within the exterior walls of the 
building and located in areas having a 
local 99 percent winter design temperature 
of 5° For higher. 

802.10.2.3 Where the vent cormector used 
for gas utilization eqiiipment having a draft 
hood or a Category I appliance is located in 
or passes through attics and crawl spaces, that 
portion Of the vent connector shall be listed 
Type B, listed Type L, or listed vent material 
having equivalent insulation qualities. 

802.10.2.4 Vent connectors for residential- 
type appliances shall comply with the 
following: 

(1) Vent connectors for listed gas 
appliances having draft hoods and for 
appliances having draft hoods and 
equipped with listed conversion 
burners that are not installed in attics. 



crawl spaces, or other unconditioned 
areas shall be one of the following: 

(a) Type B or Type L vent material. 

(b) Galvanized sheet steel not less than 
0.018 in. (0.46 mm) thick. 

(c) Aluminum (1100 or 3003 alloy or 
equivalent) sheet not less than 0.027 
in. (0.69 mm) thick. 

(d) Stainless steel sheet not less than 
0.012 in. (0.31 mm) thick. 

(e) Smooth-interior-wall metal pipe 
having resistance to heat and 
corrosion equal to or greater than 
that of b, c, or d above. 

(f) A listed vent connector. 

(2) Vent connectors shall not be covered 
with insulation. 

Exception: Listed insulated vent 
cormectors shall be installed accor- 
ding to the terms of their listing. 

802.10.2.5 A vent connector for 
noruresidential low-heat equipment shall be | 
a factory-built chimney section or steel pipe 
having resistance to heat and corrosion 
equivalent to that for the appropriate 
galvanized pipe as specified in Table 8-3. 
Factory-built chimney sections shall be 
joined together in accordance with the 
chimney manufacturer's instructions. 
[NFPA 54: 12.11.2.5] 

802.10.2.6 Vent connectors for medium- 
heat equipment and commercial and 
industrial incinerators shall be constructed 
of factory-built, medium-heat chimney 
sections or steel of a thickness not less than 
that specified in Table 8-4, and shall comply 
with the following: 

(1) A steel vent connector for equipment 
with a vent gas temperature in excess of 
1000°F (538°C) measured at the entrance 
to the connector shall be lined with 
medium-duty fire brick (ASTM C 64, 
Specification for Refractories for 
Incinerators and Boilers, Type F) or the 
equivalent. 

(2) The lining shall be at least 2-1/2 inches (64 
mm) thick for a vent connector having a 
diameter or greatest cross-sectional 
dimension of eighteen (18) inches (460 mm) 
or less. 

(3) The lining shall be at least 4-1/2 inches 
(110 mm) thick laid on the 4-1/2 inches (110 
mm) bed for a vent connector having 



120 



CHIMNEYS AND VENTS 



802.10 



n 



diameter or greatest cross-sectional 
dimensioi\ greater than eighteen (18) 
inches (460 mm). 

(4) Factory-built chimney sections, if 
employed, shall be joined together in 
accordance with the chimney manu- 
facturer's instructions. 

TABLE 8-3 

Minimum Tliici<ness for Galvanized Steei Vent 
Connectors for Low-Heat Appliances 



Diameter of Connector (in.] 



Minimum Tliicl<ness (in.) 



Less than 6 
6 to less than 10 
10 to 12 inclusive 
14 to 16 inclusive 
Over 16 



0.019 
0.023 
0.029 
0.034 
0.056 



For SI imits, 1 in. = 25.4 mm; 1 in.^ = 645 mml 
I [NFPA 54: Table 10.10.2.5] 

TABLE 8-4 

IVIinimum Thiclcness for Steel Vent Connectors 

for Medium-Heat Equipment and Commercial and 

Industrial Incinerators 

Vent Connector Size 



Diameter (in.) 



Area (in.^) 



IVIinimum 
Tliici<ness (in.) 



Up to 14 Up to 154 0.053 

Over 14 to 16 154 to 201 0.067 

Over 16 to 18 201 to 254 0.093 

Over 18 Larger than 254 0.123 



For SI imits, 1 in. = 25.4 mm; 1 in.^ 
I [NFPA 54: Table 10.10.2.6] 



: 645 mm^. 



802.10,3 Size of Vent Connector. 

802.10.3.1 A vent connector for gas 
utilization equipment with a single draft hood 
or for a Category I fan-assisted combustion 
system appliance shall be sized and installed 
in accordance with Section 803.0 or other 
approved engineering methods. 

802.10.3.2 For a single appliance having more 
than one draft hood outlet or flue collar, the 
manifold shall be constructed according to the 
instructions of the appliance manufacturer. 
Where there are no instructions, the manifold 



shall be designed and constructed in 
accordance with approved engineering 
practices. As an alternate method, the effective 
area of the manifold shall equal the combined 
area of the flue collars or draft hood outlets 
and the vent connectors shall have a minimum 
one (1) foot (0.3 m) rise. 

802.10.3.3 Where two or more gas appliances 
are connected to a common vent or clumney, 
each vent connector shall be sized in 
accordance with Section 803.0 or other 
approved engineering methods. As an 
alternative method applicable only when aU of 
the appliances are draft hood equipped, each 
vent connector shall have an effective area not 
less than the area of the draft hood outlet of 
the appliance to which it is connected. 

802.10.3.4 Where two or more gas appliances 
are vented through a common vent connector 
or vent manifold, the common vent connector 
or vent manifold shall be located at the 
highest level consistent with available head- 
room and clearance to combustible material 
and shaU be sized in accordance with Section 
803.0 or other approved engineering methods. 

As an alternate method applicable only 
where there are two draft hood-equipped 
appliances, the effective area of the common 
vent connector or vent manifold and all 
junction fittings shall be not less than the area 
of the larger vent connector plus 50 percent 
of the areas of smaller flue coUar outlets. 

802.1 0.3.5 Where the size of a vent connector 
is increased to overcome installation limita- 
tions and obtain connector capacity equal to 
the equipment input, the size increase shall 
be made at the equipment draft hood outlet. 

802.10.4 Two or More Appliances Connected 
to a Single Vent. 

802.1 0.4.1 Where two or more vent connectors 
enter a common gas vent, chimney flue, or 
single-wall metal pipe, the smaller connector 
shall enter at the highest level consistent 
with the available headroom or clearance to 
combustible material. 

802.1 0.4.2 Vent connectors serving Category 
I appliances shall not be connected to any 
portion of a mechanical draft system 
operating under positive static pressure, 
such as those serving Category III or 
Category IV appUances. 

802.10.5 Clearance. Minimum clearances from 
vent connectors to combustible material shall be 
in accordance with Table 8-2. 



121 



802.10 



2007 CALIFORNIA MECHANICAL CODE 



Exception: The clearance between a vent 
connector and combustible material shall 
be permitted to be reduced where the 
combustible material is protected as 
specified for vent connectors in Table 5-3. 

802.10.6 Avoid Unnecessary Bends. A vent 
connector shall be installed so as to avoid turns 
or other construction features that create 
excessive resistance to flow of vent gases. 

802.10.7 Joints. Joints between sections of 
connector piping and coimections to flue collars 
or draft hood outlets shall be fastened in 
accordance with one of the following methods: 

(1) By sheet metal screws. 

(2) Vent connectors of listed vent material shall 
be assembled and connected to flue collars 
or draft hood outlets in accordance with 
the manufacturers' instructions. 

(3) Other approved means. 

802.10.8 Slope. A vent connector shall be 
installed without any dips or sags and shall 
slope upward toward the vent or chimney at 
least 1/4 in. /ft. (20 mm/m). 

Exception: Vent connectors attached to a 
mechanical draft system installed in accor- 
dance with the manufacturers' instructions. 

802.10.9 Lengtli of Vent Connector. 

802.10.9.1 A vent connector shall be as 
short as practical, and the gas utilization 
equipment located as close as practical to 
the chimney or vent. 

802.1 0.9.2 The maximum horizontal length 
of a single-wall connector shall be 75 percent 
of the height of the chimney or vent except 
for engineered systems. The maximum 
length of an individual connector for a 
chimney or vent system serving multiple 
appliances, from the appliance outlet to the 
jimction with the common vent or another 
connector, shall be 100 percent of the height 
of the chimney or vent. [NFPA 54:12.11.9.2] 

802.10.9.3 The maximum horizontal length 
of a Type B double-wall connector shaU be 
100 percent of the height of the chimney or 
vent, except for engineered systems. The 
maximtim length of an individuall connector 
for a chimney or vent system serving multiple 
appliances, from the appliance outlet to the 
junction with the common vent or another 
connector, shall be 100 percent of the height 
of the chimney or vent. [NFPA 54: 12.11.9.3] 

802.10.10 Support. A vent coimector shall be 
supported for the design and weight of the 



material employed to maintain clearances and 
prevent physical damage and separation of joints. 

802.10.11 Chimney Connection. Where entering 
a flue in a masonry or metal chimney, the vent 
coimector shall be installed above the extreme 
bottom to avoid stoppage. Where a thimble or 
slip joint is used to facilitate removal of the 
connector, the connector shall be firmly attached 
to or inserted into the thimble or slip joint to 
prevent the connector from falling out. Means 
shall be employed to prevent the connector from 
entering so far as to restrict the space between its 
end and the opposite wall of the chimney flue. 

802.10.12 Inspection. The entire length of a 
vent coimector shall be readily accessible for 
iaspection, cleaning, and replacement. 

802.10.13 Fireplaces. A vent connector shall 
not be connected to a chimney flue serving a 
fireplace unless the fireplace flue opening is 
permanently sealed. 

802.10.14 Passage Through Ceilings, Floors, 
or Walls. 

802.10.14.1 A vent connector shall not pass 
through any ceiling, floor, or fire-resistance 
rated waU. A single-wall metal pipe connector 
shall not pass through any interior wall. 

Exception: Vent connectors made of listed 
Tj^e B or Type L vent material and serving 
listed equipment with draft hoods and other 
equipment listed for use with Type B gas 
vents that pass through walls or partitions 
constructed of combustible material shall be 
installed with not less than the listed 
clearance to combustible material. 

802.10.14.2 A vent connector made of a 
single-wall metal pipe shall not pass 
through a combustible exterior wall unless 
guarded at the point of passage by a 
ventilated metal thimble not smaller than 
the following: 

(1) For listed appliances equipped with 
draft hoods and appliances listed for use 
with Type B gas vents, the thimble shall 
be a minimiun of four (4) inches (100 mm) 
larger in diameter than the vent connector. 
Where there is a run of not less than six 
(6) feet (1.8 m) of vent coimector in the 
opening between the draft hood outlet 
and the thimble, the thimble shall be a 
minimum of two (2) inches (50 mm) 
larger in diameter than the vent connector. 



122 



CHIMNEYS AND VENTS 



802.10-802.15 



(2) For unlisted appliances having draft 
hoods, the thimble shall be a mirummn 
of six (6) inches (150 mm) larger in 
diameter than the vent connector. 

(3) For residential and low^-heat appliances, 
the thimble shall be a minimum of 
twelve (12) inches (300 mm) larger in 
diameter than the vent connector. 

Exception: In lieu of thimble protec- 
tion, all combustible material in the 
wall shall be removed from the vent 
connector a sufficient distance to 
provide the specified clearance 
from such vent connector to 
combustible material. Any material 
used to close up such opening shall 
be noncombustible. 

802.10.14.3 Vent connectors for medium- 
heat equipment shall not pass through walls 
or partitions constructed of combustible 
I material. [NFPA 54:10.10.14.3] 

802.1 1 Vent Connectors for Category II, Category 
III, and Category IV Gas Utilization Equipment. 

(See Section 802.4.) [NFPA 54:10.11] 

802.12 Draft Hoods and Draft Controls. 

802.12.1 Equipment Requiring Draft Hoods. 

Vented gas utilization equipment shall be 
installed with draft hoods. 

Exception: Dual oven-type combination 
ranges; incinerators; direct-vent equipment; 
fan-assisted combustion system appliances; 
equipment requiring chimney draft for 
operation; single-firebox boilers eqmpped with 
conversion biomers with inputs greater than 
400,000 Btu/h (117 kW); equipment equipped 
with blast, power, or pressure burners tliat are 
not listed for use with draft hoods; and 
eqviipment designed for forced venting. 

802.12.2 Installation. A draft hood supplied 
with or forming a part of listed vented gas 
utilization equipment shall be installed without 
alteration, exactly as furnished and specified by 
the equipment manufacturer. If a draft hood is 
not supplied by the equipment manufacturer 
where one is required, a draft hood shall be 
installed, be of a listed or approved type, and, in 
the absence of other instructions, be of the same 
size as the equipment flue collar. Where a draft 
hood is required with a conversion burner, it 
shall be of a listed or approved type. Where it is 
determined that a draft hood of special design is 

■ needed or preferable for a particular installation, 
the installation shall be in accordance with the 
recommendations of the equipment manufac- 



turer and shall be with the approval of the 
Authority Having Jurisdiction. 

802.12.3 Draft Control Devices. Where a draft 
control device is part of the gas utilization 
equipment or is supplied by the equipment 
manufacturer, it shall be installed in accordance 
with the manufacturer's instructions. In the 
absence of manufacturer's instructions, the device 
shall be attached to the flue collar of the equipment 
or as near to the equipment as practical. 

802.12.4 Additional Devices. Gas utilization 
equipment (except incinerators) requiring 
controlled chimney draft shall be permitted to be 
equipped with a listed double-acting barometric 
draft regulator installed and adjusted in 
accordance with the manufacturers' instructions. 

802.12.5 Location. Draft hoods and barometric 
draft regulators shall be installed in the same 
room or enclosure as the equipment in such a 
manner as to prevent any difference in pressure 
between the hood or regulator and the 
combustion air supply. 

802.12.8 Positioning. Draft hoods and draft 
regulators shall be installed in the position for 
that they were designed with reference to the 
horizontal and vertical planes and shall be 
located so that the relief opening is not 
obstructed by any part of the equipment or 
adjacent construction. The equipment and its 
draft hood shall be located so that the relief 
opening is accessible for checking vent operation. 

802.12-7 Clearance. A draft hood shall be 
located so that its relief opening is not less than 
six (6) inches (150 mm) from any surface except 
that of the equipment it serves and the venting 
system to which the draft hood is connected. 
Where a greater or lesser clearance is indicated 
on the equipment label, the clearance shall not 
be less than that specified on the label. Such 
clearances shall not be reduced. [NFPA 54:10.12] j 

802.13 Manually Operated Dampers. A manually 
operated dam.per shall not be placed in any equipment 
vent connector. Fixed baffles shall not be classified as 
manually operated dampers. [NFPA 54:10.13] | 

802.14 Automatically Operated Vent Dampers. An 

automatically operated vent damper shall be of a listed 
type. [NFPA 54:10.14] | 

802.15 Obstructions. Devices that retard the flow of 
vent gases shaU not be installed in a vent connector, 
chimney, or vent. The following shall not be 
considered as obstructions: 

(1) Draft regulators and safety controls 
specifically listed for installation in venting 



123 



802.15-803.1 



2007 CALIFORNIA MECHANICAL CODE 



systems and installed in accordance with the 
terms of theit listing. 

(2) Approved draft regulators and safety 
controls designed and installed in. accordance 
with approved engineering methods. 

(3) Listed heat reclaimers and automatically 
operated vent dampers installed in accor- 
dance with the terms of their listing. 

(4) Vent dampers serving listed appliances 
installed in accordance with Sections 803.1 
and 803.2.1 or other approved engineering 
methods. 

(5) Approved economizers, heat reclaimers, 
and recuperators installed in venting 
systems of equipment not required to be 
equipped with draft hoods, provided the 
gas utilization equipment manufacturer's 
instructions cover the installation of such a 
device in the venting system and performance 
in accordance with Sections 802.3.1 and 
802.3.2 is obtained. [NFPA 54:10.15] 

803.0 Sizing of Category I Venting Systems 

803.1 These venting tables shall not be used where 
obstructions (see Section 802.15) are installed in the 
venting systent. The installation of vents serving 
listed appliances with vent dampers shall be in 
accordance with the appliance manufacturer's 
instructions or in accordance with the following: 

(1) The maximum capacity of the vent system 
shall be determined using ..the NAT Max 
column. 

(2) The minimum capacity shall be determined 
as if the appliance were a fan-assisted 
appliance, using the FAN Min column to 
determine the minimum capacity of the 
vent system. Where the corresponding 
FAN Min is NA, the vent configuration shall 
not be permitted and an alternative 
venting configuration shall be utilized. 

803.1.1 Where the vent size determined from 
the tables is smaller than the appliance draft 
hood outlet or flue collar, the use of the 
smaller size shall be permitted provided that 
the installation complies with all of the 
following requirements: 

(1) The total vent height (H) is at least ten (10) 
feet (3 m). 

(2) Vents for appliance draft hood outlets or flue 
collars twelve (12) inches (300 mm) in 
diameter or smaller are. not reduced more 
than one table size. 



(3) Vents for appliance draft hood outlets or 
flue collars larger than twelve (12) inches 
(300 mm) in diameter are not reduced more 
than two table sizes. 

(4) The maximum capacity listed in the tables 
for a fan-assisted appliance is reduced by 
ten (10) percent (0.90 maximvun table capacity). 

(5) The draft hood outlet is greater than four (4) 
inches (100 mm) in diameter. Do not connect 
a three (3) inches (80 mm) diameter vent to a 
four (4) inches (100 mm) diameter draft 
hood outlet. This provision shall not apply 
to fan-assisted appliances. 

803.1.2 Single-appliance venting configurations 
with zero (0) lateral lengths in Tables 8-5, 8-6, 
and 8-9 shall not have elbows in the venting 
system. For vent configurations with lateral 
lengths, the venting tables include allowance for 
two 90 degree turns. For each additional elbow 
up to and including 45 degrees, the maximum 
capacity listed in the venting tables shall be 
reduced by 5 percent. For each elbow greater 
than 45 degrees up to and including 90 degrees, 
the maximum capacity listed in the venting 
tables shall be reduced by 10 percent. 

803.1.3 Zero (0) lateral (L) shall apply oiily to a 
straight vertical vent attached to a top-outlet 
draft hood or flue collar. 

803.1.4 Sea level input ratings shall be used 
when determining maximum capacity for high- 
altitude installation. Actual input (derated for 
altitude) shall be used for determining minimum 
capacity for high-altitude installation. 

803.1 .5 For appliances with more than one input 
rate, the minimum vent capacity (FAN Min) 
determined from the tables shall be less than the 
lowest appliance input rating, and the maximum 
vent capacity (FAN Max/NAT Max) determined 
from the tables shall be greater than the highest 
appliance rating input. 

803.1 .6 Listed corrugated metallic chimney liner 
systems in masoriry chimneys shall be sized by 
using Table 8-5 or 8-6 for Type B vents, with the 
maximum capacity reduced by 20 percent (0.80 
maximum capacity) and the minimum capacity 
as shown in Table 8-5 or 8-6. Corrugated metallic 
liner systems installed with bends or offsets shall 
have theif maximum capacity further reduced in 
accordance with Section 803.1.2. The 20 percent 
reduction for corrugated metallic chimney liner 
systems includes an allowance for one long 
radius 90 degree turn at the bottom of the liner. 

803.1.7 Where the vertical vent has a larger 
diameter than the vent cormector, the vertical 



124 



CHIMNEYS AND VENTS 



803.1 -803.2 



vent diameter shall be used to determine the 
minimum vent capacity, and the connector 
diameter shall be used to determine the 
maximum vent capacity. The flow area of the 
vertical vent shall not exceed seven times the 
flow area of the hsted appliance categorized vent 
area, flue collar area, or draft hood outlet area 
unless designed in accordance with approved 
engineering methods. 

803.1.8 Connection to Chimney Liners. 

Connections between chimney liners and listed 
double-wall connectors shall be made with listed 
adapters designed for such purpose. [NFPA 
54:13.1.8] 

803.1.8.1 Tables 8-5 through 8-9 shall be 
used for chimneys and vents not exposed to 
the outdoors below the roof line. A T5^e B 
vent or listed chimney lining system passing 
through an unused masonry chimney flue 
shall not be considered to be exposed to the 
outdoors. A Type B vent passing through an 
tinventilated enclosure or chase insulated to 
a value of not less than R8 shall not be 
considered to be exposed to the outdoors. 
Table 8-7 in combination with Table 8-15 
shall be used for clay-tile-lined exterior 
masonry chimneys, provided all of the 
following are met: 

(1) The vent connector is Type B double wall., 

(2) The vent connector length is limited to 
1-1/2 feet for each inch (180 mm/mm) of 
vent connector diameter. 

(3) The appliance is draft hood equipped. 

(4) The input rating is less than the maximum 
capacity given in Table 8-7. 

(5) For a water heater, the outdoor design 
temperature shall not be less than 5°F 
(-15°C). 

(6) For a space-heating appliance, the input 
rating is greater than the minimum 
capacity given by Table 8-15. 

(7) Where the conditions of 803.1.8.1(1)' 
through (6) cannot be met, an alternative 
venting design shall be used, such as a 
listed chimney lining system. 

Exception: Vents serving listed appliances 
installed in accordance with the appliance 
manufacturer's instructions and the 
terms of the listing. 

803.1 .9 Corrugated vent connectors shall not be 
smaller than the listed appliance categorized 
vent diameter, flue collar diameter, or draft 
hood outlet diameter. 



803.1.9.1 Vertical Vent Upsizing/7 Times 
Rule. Where the vertical vent has a larger 
diameter than the vent connector, the 
vertical vent diameter shall be used to 
determine the mirumum vent capacity, and 
the connector diameter shall be used to 
determine the maximxun vent capacity. The 
flow area of the vertical vent shall not exceed 
seven times the flow area of the listed 
appliance categorized vent area, flue collar 
area, or draft hood outlet area unless 
designed in accordance with approved 
engineering methods. [NFPA 54: 13.1.9] 

803.1.10 Vent connectors shall not be upsized 
more than two sizes greater than the listed 
appliance categorized vent diameter, flue collar 
diameter, or draft hood outlet diameter. 

803.1.11 In a single run of vent or vent connec- 
tor, more than one diameter and type shall be 
permitted to be used, provided that all the sizes 
and types are permitted by the tables. 

803.1.12 Interpolation shall be permitted in 
calculating capacities for vent dimensions that 
fall between table entries. (See Example 8-1 in 
Section 803.2.23.) 

803.1.13 Extrapolation beyond the table entries 
shall not be permitted. 

For Sl'units, 1 in. = 25.4 mm; 1 ft. = 0.305 m; 
1,000 Btu/h = 0.293 kW; 1 in.^ = 645 mm^ 

803.1.14 For vent heights lower than six (6) feet 
and liigher than shown in the tables, engineering 
methods shall be used to calculate vent capacities. 
[NFPA 54:13.1] 

803.1.15 Draft IHood Conversion Accessories. 
Draft hood conversion accessories for use with 
masonry chimneys venting listed Category I fan- 
assisted appliances shall be listed and installed 
in accordance with the listed accessory 
mainufacturers' installation instructions. [NFPA 
54:13.1.10] 

803.2 Additional Requirements to Multiple 
Appliance Vent. 

803.2.1 These venting tables shall not be used 
where obstructions (see Section 802.15) are 
installed in the venting system. The installation 
of vents serving listed appliances with vent 
dampers shall' be in accordance with the 
appliance manufacturer's instructions or in 
accordance with the following: 

(1) The maximum capacity of the vent 
connector shall be determined using the 
NAT Max column. 



125 



803.2 - Figure 8-4 



2007 CALIFORNIA MECHANICAL CODE 



(2) The maximiun capacity of the vertical vent 
or chimney shall be determined using the 
FAN+NAT column when the second 
appliance is a fan-assisted appliance, or the 
NAT+NAT column when the second 
appliance is eqtiipped with a draft hood. 

(3) The minimum capacity shall be determined 
as if the appliance were a fan-assisted 
apphance. 

(a) The minimum capacity of the vent 
cormector shall be determined using the 
FAN Min column. 

(b) The FAN+FAN column shall be used 
when the second appliance is a fan- 
assisted appliance, and the FAN+NAT 
colimm shall be used when the second 
appliance is equipped with a draft 
hood, to determine whether the vertical 
vent or chimney configuration is not 
permitted (NA). Where the vent 
configuration is NA, the vent con- 
figuration shall not be permitted, 
and an alternative venting configxiration 
shall be utilized. 

803.2.2 The maximum vent connector horizontal 
length shall be 18 in. /in. (180 mm/mm) of 
connector diameter as follows: 



Connector 


Connector l-lorizontal 


Diameter Maximum 


Length 


(in.) 


(ft.) 


3 


4-1/2 


4 


6 


5 


7-1/2 


6 


9 


7 


10-1/2 


8 


12 


9 


13-1/2 


10 


15 


12 


18 


14 


21 


16 


24 


18 


27 


20 


30 


22 


33 


24 


36 



Manifold common 
vent connector 



-lm- 

1. 



T 

L 



Connectors 

^ 1». 



g 



T 

D 



EL 



H 



For SI tmits, 1 in. = 25.4 mm; 1 ft. = 0.305 m. 



FIGURE 8-4 Use of iUlanifolded Common Vent 
Connector. 

803.2.3 The vent connector shall be routed to the 
vent utilizing the shortest possible route. 
Connectors with longer horizontal lengths than 
those listed in Section 803.2.2 are permitted 
tinder the following conditions: 

(A) The maximiun capacity (FAN Max or NAT 
Max) of the vent connector shall be reduced 
10 percent for each additional multiple of 
the length listed in 803.2.2. For example, the 
maximum length listed for a four (4) inches 
(100 mm) cormector is six (6) feet (1.8 m). 
With a connector length greater than six (6) 
feet (1.8 m) but not exceeding twelve (12) 
feet (3.7 m), the maximtim capacity must be 
reduced by ten (10) percent (0.90 maximum 
vent connector capacity). With connector 
length greater than twelve (12) feet (3.7 m) 
but not exceeding eighteen (18) feet (5.5 m), 
the maximum capacity must be reduced by 
20 percent (0.80 maximuutn vent capacity). 

(B) For a connector serving a fan-assisted 
appliance, the minimum capacity (FAN 
Min) of the connector shall be determined 
by referring to the corresponding single- 
appliance table. For Type B double-wall 
connectors. Table 8-5 shall be used. For 
single-wall connectors. Table 8-6 shall be 
used. The height (H) and lateral (L) shall be 
measured accorditig to the procedures for a 
single-appliance vent, as if the other 
appliances were not present. 



126 



CHIMNEYS AND VENTS 



Figure 8-5 - 803.2 



Vent connector Tee 



G 



\ 




Tee same size as 
segment above 



Common vent size 
based on all inputs " 

entering this segment 
and available total height 



Total input 



Rise 
C, — pl'^ Increase 



Available total 
height H equals 
rise plus distance 
between tees 



Tee same 
«--'size as 
segment 
above 




vent 
connector 
size if 
necessary 



W////////A 



^=}^ 



Other inputs 
from below 



Multistory gas vent design procedure for each segment 
of system 

Vent connector size Common vent size 

depends on: depends on: 

• Input • Combined inputs 

• Rise • Available total height H 

• Available total height H • Table 8-1 common 

• Table 8-1 connectors vent 

FIGURE 8-5 Multistory Gas Vent Design 
Procedure for Each Segment of System. 

803.2.4 Where the vent connectors are combined 
prior to entering the vertical portion of the 
cominon vent to form a common vent manifold, 
the size of the cominon vent manifold and the 
common vent shall be determined by applying a 
10 percent reduction (0.90 x maximum common 
vent capacity) to the Common Vent Capacity part 
of the common vent tables. The length of the 
common vent connector manifold (JJA) shall not 
exceed 18 in./in. (180 nun/mm) of common vent 
connector manifold diameter (D). (See Figure 8-4.) 

803.2.5 Where the common vertical vent is 
offset, the maximum capacity of the common 
vent shall be reduced in accordance with Section 
803.2.6, and the horizontal length of the cominon 
vent offset shall not exceed 18 in./in. (180 
mm/mm) of common vent diameter. 



803.2.6 For each elbow up to and including 45 
degrees in the common vent, the maximum 
common vent capacity listed in the venting 
tables shall be reduced by 5 percent. For each 
elbow greater than 45 degrees up to and 
including 90 degrees, the maximum common 
vent capacity listed in the venting tables shall be 
reduced by 10 percent. 

803.2.7 The vent connector capacities listed in 
the common vent sizing tables include 
allowance for two 90 degree elbows. For each 
additional elbow up to and including 45 
degrees, the maximum vent connector capacity 
listed in the venting tables shall be reduced by 5 
percent. For each elbow greater than 45 degrees 
up to and including 90 degrees, the maximum 
vent connector capacity listed in the venting 
tables shall be reduced by 10 percent. 

803.2.8 Common Vent Minimum Size. The 

cross-sectional area of the common vent shall be 
equal to or greater than the cross-sectional area 
of the largest connector. [NFFA 54: 13.2.8] 

803.2.9 Tee and Wye Fittings. Tee and wye 

fittings connected to a comm.on vent shall be 
considered as part of the common vent and 
constructed of materials consistent with that of 
the common vent. [NFPA 54:13.2.9] 

803.2.9.1 At the point where tee or wye 
fittings connect to a common vent, the 
opeiiing size of the fitting shall be equal to 
the size of the common vent. Such fittings 
shall not be prohibited from having reduced 
size openings at the point of connection of 
appliance vent connectors. 

803.2.10 Sea level input ratings shall be used 
when determining maximum capacity for high- 
altitude installation. Actual input (derated for 
altitude) shall be used for determining minimum 
capacity for high-altitude installation. 

803.2.1 1 The connector rise (K) for each appliance 
connector shall be measured from the draft hood 
outlet or flue collar to the centerline where the 
vent gas streams come together. 

803.2.12 For multiple units of gas utilization 
equipment all located on one floor, available 
total height (H) shall be measured from the 
highest draft hood outlet or flue collar up to the 
level of the outlet of the common vent. 

803.2.13 For multistory installations, available 
total height (H) for each segment of the system 
shall be the vertical distance between the highest 
draft hood outlet or flue collar entering that 
segment and the centerline of the next higher 
interconnection tee. (See Figure 8-5.) 



127 



803.2 - Figure 8-6 



2007 CALIFORNIA MECHANICAL CODE 



803.2.14 The size of the lowest connector and of 
the vertical vent leading to the lowest 
interconnection of a multistory system shall be 
in accordance with Table 8-5 or 8-6 for available 
total height (H) up to the lowest interconnection. 
(See Figure 8-6.) 

803.2.15 Where used in multistory systems, 
vertical common vents shall be Type B double- 
waU and shall be installed with a listed vent cap. 

803.2.16 Offsets in multistory common vent 
systems shall be limited to a single offset in each 
system, and systems with an offset shall comply 
with all of the following: 

(1) The offset angle shall not exceed 45 degrees 
from vertical. 

(2) The horizontal length of the offset shall not 
exceed eighteen (18) inches for each inch (180 
mm/mm) of common vent diameter of the 
segment in that the offset is located. 

(3) For the segment of the common vertical vent 
containing the offset, the common vent 
capacity listed in the common venting tables 
shall be reduced by 20 percent (0.80 x 
maximum common vent capacity). 

(4) A multistory common vent shall not be 
reduced in size above the offset. 

803.2.17 Where two or more appliances are 
connected to a vertical vent or chimney, the flow 
area of the largest section of vertical vent or 
chimney shall not exceed seven times the smallest 
listed appliance categorized vent areas, flue collar 
area, or draft hood outlet area, imless designed in 
accordance with approved engineering methods. 

803.2.18 For appliances with more than one 
input rate, the mirdmimn. vent connector capacity 
(FAN Min) determined from the tables shall be 
less than the lowest appliance input rating, and 
the maximum vent connector capacity (FAN Max 
or NAT Max) determined from the tables shall be 
greater than the highest appUance input rating. 

803.2.19 Listed, corrugated metallic chimney 
liner systems in masonry chimneys shall be 
sized by using Table 8-10 or 8-11 for Type B 
vents, with the maximum capacity reduced by 
20 percent (0.80 maximum capacity) and the 
minimiim capacity as shown in Table 8-10 or 8-11. 
Corrugated metallic liner systems installed with 
bends or offsets shall have their maximum 
capacity further reduced in accordance with 
Sections 803.2.5 and 803.2.6. The 20 percent 
reduction for corrugated metallic chimney liner 
systems includes an allowance for one long 
radius 90 degree turn at the bottom of the liner. 



803.2.20 Tables 8-10 and 8-11 shall be used for 
chimneys and vents not exposed to the outdoors 
below the roof line. A Type B vent passing 
through an unventilated enclosure or chase 
insulated to a value of not less than R8 shall not 
be considered to be exposed to the outdoors. 
Tables 8-16 through 8-19 shall be used for clay- 
tile-lined exterior masonry chimneys, provided 
all of the following conditions are met: 

(1) Vent coimector is Type B double-wall. 

(2) At least one appliance is draft hood-equipped. 

(3) The combined appliance input rating is less 
than the maximimi capacity given by Table 
8-16 (for NAT+NAT) or Table 8-18 (for 
FAN+NAT). 

(4) The input rating of each space-heating 
appliance is greater than the minimum 
input rating given by Table 8-17 (for 
NAT+NAT) or Table 8-19 (for FAJST+NAT). 



use inaiviauai vent tor 
top-floor appliance if 

connector "^'^j 

requirement ] ] 
for rise or total i i 
height cannot 
be met 



Listed cap 



Use vent 
connector - 
table 



Top-floor 
appliance 



I I 



Available total 
height for top-floor 
appliance 



Rise 



^=4> 



Available total 
height for third- 
floor appliance 



Use vent 

connector 

table 



Third-floor 
appliance 




Rise 



T^ 



Available total 
height for second- 
floor appliance 



Use vent 

connector. 

table ^^Rise 



Second-floor 
appliance 



CW 



■XJ 



use avaitaoie lotai 
height for top-floor 
appliance and 
combined input of 
all appliances on 
common vent 

^Third 
interconnection tee' 



Available total height 
for third-floor appliance 
, and combined input of 
three appliances (if top- 
floor appliance is not 
connected, measure 
total height to vent top) 

^ Second 
interconnection tee' 



Use available total height 
for second-floor appliance 
and combined heat input 
of two appliances 

First interconnection tee' 



Design vent connector for 
first-floor appliance as an 
individual vent of this total 
height for input of first-floor 
appliance 



Tee w/lth cap optional 



3 



First-floor 
appliance 



~V 



' Each interconnection tee is same size as 
segment of common vent directly above 



FIGURE 8-6 Principle of Design of Multistory 
Vents Using Vent Connector and Common Vent 
Design Tables. 



128 



CHIMNEYS AND VENTS 



803.2 



o 



(5) The vent connector sizing is in accordance 
with Table 8-12. 

(6) Where these conditions cannot be met, an 
alternative venting design shall be used, 
such as a listed chimney lining system. 

Exception: Vents serving listed appliances 
installed in accordance with the appliance 
manufacturer's installation instructions. 

803.2.21 Vent connectors shall not be increased 
more than two sizes greater than the listed 
appliance categorized vent diameter, flue collar 
diameter, or draft hood outlet diameter. Vent 
connectors for draft hood-equipped appliances 
shall not be smaller than the draft hood outlet 
diameter. Where a vent connector size(s) 
determined from the tables for a fan-assisted 
appliance(s) is smaller than the flue collar 
diameter, the use of the smaller size(s) shall be 
permitted provided that the installation 
complies with all of the following: 

(1) Vent connectors for fan-assisted appliance 
flue collars twelve (12) inches (300 mm) in 
diameter or smaller are not reduced by more 
than one table size [e.g., 12 in. to 10 in. (300 
mm to 250 mm) is a one-size reduction] and 
those larger than twelve (12) inches (300 nun) 
in diameter are not reduced more than two 
table sizes [e.g., 24 in. to 20 in. (610 mm to 510 
mm) is a two-size reduction]. 

(2) The fan-assisted appliance(s) is common 
vented with a draft hood equipped appliance(s). 

(3) The vent connector has a smooth interior 
wall. 

803.2.22 All combinations of pipe sizes and 
single-wall and double-wall metal pipe shall be 
allowed within any connector run(s) or within 
the common vent provided ALL of the 
appropriate tables permit ALL of the desired 
sizes and types of pipe, as if they were used for 
the entire length of the subject connector or vent. 
Where single-wall and Type B double-wall metal 
pipes are used for vent connectors within the 
same venting system, the common vent must be 
sized using Table 8-11 or 8-13, as appropriate. 

803.2.23 Where a table permits more than one 
diameter of pipe to be used for a connector or 
vent, all the permitted sizes shall be permitted to 
be used. 

803.2.24 Interpolation shall be permitted in 
calculating capacities for vent dimensions that 
fall between table entries. (See Example 8-1.) 

Example 8-1: interpolating between Table 



Values. An installer has an 80,000 Btu/h. input 
appliance with a four (4) inches diameter draft 
hood outlet that needs to be vented into a twelve 
(12) foot high Type B vent. The vent connector 
has a five (5) foot lateral length and is also Type 
B. Can this appliance be vented using a four (4) 
inch diameter vent? 

Solution 

Table 8-5 is used in the case of an all Type B 
vent system. However, since there is no entry 
in Table 8-5 for a height of 12 ft., interpolation 
must be used. Read down the 4 in. diameter 
NAT Max colurrm to the row associated with 
10 ft. height and 5 ft. lateral to find the capacity 
value of 77,000 Btu/h. Read further down to 
the 15 ft. height, 5 ft. lateral row to find the 
capacity value of 87,000 Btu/h. The difference 
between the 15 ft. height capacity value and 
the 10 ft. height capacity value is 10,000 Btu/h. 
The capacity for a vent system with a 12 ft. 
height is equal to the capacity for a 10 ft. height 
plus 2/5 of the difference between the 10 ft. 
and 15 ft. height values, or 77,000 + 2/5 x 
10,000 = 81,000 Btu/h. Therefore, a 4 in. 
diameter vent can be used in the installation. 

803.2.25 Extrapolation beyond the table entries 
shall not be permitted. 

803.2.26 For vent heights lower than six (6) feet 
and higher than shown in the tables, engineering 
methods shall be used to calculate vent 
capacities. [NFPA 54:13.2] 



129 



Table 8-5 



2007 CALIFORNIA MECHANICAL CODE 



Table 8-5 Type B Double-Wall Gas Vent with Single Appliance Connected Directly to Vent [NFPA 54:Table 13.1(a)] I 





Number of Appliances: 


Single 




Appliance Type: 


Category I 




Appliance Vent Connection: 


Connected Directly to Vent 



Vent Diameter — D (in.) 





Lateral 




3 


1 


4 1 5 


1 


6 




7 




8 






9 




Height 








Appliance Input Rating in Thousands of Btu per 


Hour 












H 


L 
(ft) 


FAN 
Min Max 


Max 


Vj 
Min 


VN KSf 


FAN 
Min Max 


NAT 


FAN 
Min Max 


NAT 
Max 


FAN KST 
Min Max jVIax 


FAN 
Min Max 


NAT 
Max 

..■;;. 

370 


FAN 


NAT, 


(ft) 


Max 


Vlax 


Min 


Max 


Maxl 


6 








78 


:>46 





152 


•86 


251 


141 





375 


205 





524 


285 





698 





897 


470' 




2 


13 


51 


•-36 


18 


97 


■•67 


27 157 


105 


32 


232 


157 


44 


321 


217 


53 


425 


.285 


63 


543 


370 • 




4 


21 


49 


764 


30 


94 


.■64 


39 153 


ao3 


50 


227 


153 


66 


316 


211 


79 


419 


'-279 


93 


536 


362 




6 


25 


46 


'4%1 


36 


91 


'•61 


47 149 


'100 


59 


223 


■,149 


78 


310 


205' 


93 


413 


'273 


110 


530 


354; 


8 








84 


tm 





165 


■u 


276 


^155 





415 


%S 





583 


520 





780 


•415 





1006 


■5371 




2 


12 


57 


tn40 


16 


109 


■■75 


25 178 


nio 


28 


263 


"ISO 


42 


365 


■247 


50 


483 


•322 


60 


619 


418 j 




5 


23 


53 


558 


32 


103 


/71 


42 171 


tl-15 


53 


255 


,173 


70 


356 


237 


83 


473 


-313 


99 


607 


407 




8 


28 


49 


■m 


39 


98 


.-.66 


51 164 


1109 


64 


247 


•165 


84 


347 


■227, 


99 


463 


303 


117 


596 


396 


10 








88 


% 





175 


100 


295 


•1-66 





447 


'255 





631 


345' 





847 


450 





1096 


,. 1 
585 i 




2 


12 


61 


t42 


17 


118 


VSl 


23 194 


129 


26 


289 


195 


40 


402 


273. 


48 


533 


■355 


57 


684 


457! 




5 


23 


57 


•40 


32 


113 


'V? 


41 187 


124 


52 


280 


188 


68 


392 


263 


81 


522 


346 


95 


671 


446: 




10 


30 


51 


='36 


41 


104 


•70 


54 176 


ai5 


67 


267 


175 


88 


376 


245, 


104 


504 


,330 
525 


122 


651 


427, 


15 








94 


^58 





191 


'112 


327 


187 





502 


im 





716 


390 





970 





1263 


682' 




2 


11 


69 


■m 


15 


136 


i-93 


20 226 


150 


22 


339 


.225 


38 


475 


'316 


45 


633 


414 


53 


815 


544- 




5 


22 


65 




30 


130 


l87 


39 219 


|I42 
135 


49 


330 


m? 


64 


463 


,300' 


76 


620 


:403 


90 


800 


.529' 




10 


29 


59 


-41 


40 


121 


(-82 


51 206 


64 


315 


*m 


84 


445 


»288 


99 


600 


-.-386 


116 


777 


507, 




15 


35 


53 


•B7 


48 


112 


i76 


61 195 


ms 


76 


301 


198 


98 


429 


(275, 


115 


580 


-373 


134 


755 


491 


20 








97 


^1 





202 


1.119 


349 


&2 





540 


r307 





776 


430, 





1057 


■575 





1384 


752' 




2 


10 


75 


" 


14 


149 


■100 


18 250 


m 


20 


377 


•249 


33 


531 


346' 


41 


711 


470 


50 


917 


612, 




5 


21 


71 




29 


143 


•:96 


38 242 


mo 


47 


367 


k241 


62 


519 


337, 


73 


697 


460 


86 


902 


599 




10 


28 


64 




38 


133 


t89 


50 229 


150 


62 


351 


;228 


81 


499 


321 


95 


675 


'.443 


112 


877 


576 • 




15 


34 


58 




46 


124 


r84 


59 217 


142 


73 


337 


217 


94 


481 


308 


111 


654 


-427 


129 


853 


557 




20 


48 


52 


64 


55 


116 


.,78 


69 206 


l34 


84 


322 


206 


107 


464 


295 


125 


634 


410 


145 


830 


537, 


30 








100 





213 


128 


374 


770 





587 


'336 





853 


!475 





1173 


.650| 





1548 


855; 




2 


9 


81 


,56 


13 


166 


.112 


14 283 


185 


18 


432 


280 


27 


613 


394 


33 


826 


^535' 


42 


1072 


7001 




5 


21 


17 


54 


28 


160 


108 


36 275 


176 


45 


421 


,273 


58 


600 


385 


69 


811 


-,524| 


82 


1055 


688 




10 


27 


70 


.•50 


37 


150 


102 


48 262 


171 


59 


405 


361 


77 


580 


371 ; 


91 


788 


^■507! 


107 


1028 


668 




15 


33 


64 


NA 


44 


141 


96 


57 249 


163 


70 


389 


:249 


90 


560 


357 


105 


765 


'490 


124 


1002 


648 




20 


56 


58 


NA 


53 


132 


90 


66 237 


154 


80 


374 


,•237 


102 


542 


343 


119 


743 


-473 


139 


977 


628 i 




30 


NA 


NA 


NA 


73 


113 


NA 


88 214 


NA 


104 


346 


219 


131 


507 


321 ; 


149 


702 


444 


171 


929 


5941 


50 








101 


•67 





216 


134 


397 


232 





633 


•363 





932 


518 





1297 


.-'708 





1730 


=952! 




2 


8 


86 


61 


11 


183 


122 


14 320 


206 


15 


497 


314 


22 


715 


445 


26 


975 


.,615 


33 


1276 


813' 




5 


20 


82 


NA 


27 


177 


119 


35 312 


200 


43 


487 


308 


55 


702 


438 


65 


960 


605 


77 


1259 


'798' 




10 


26 


76 


NA 


35 


168 


114 


45 299 


190 


56 


471 


298 


73 


681 


.426! 


86 


935 


589 


101 


1230 


•773' 




15 


59 


70 


NA 


42 


158 


■NA 


54 287 


180 


66 


455 


•288 


85 


662 


,413 


100 


911 


572 


117 


1203 


747: 




20 


NA 


NA 


NA 


50 


149 


•NA 


63 275 


169 


76 


440 


278 


97 


642 


.401, 


113 


888 


-556 


131 


1176 


7221 




30 


NA 


NA 


NA 


69 


131 


NA 


84 250 


J<IA 


99 


410 


.?59 


123 


605 


376' 


141 


844 


V522 


161 


1125 


670 i 


100 





NA 


NA 


NA 





218 


NA 


407 


NA 





665 


'400 





997 


560 





1411 


'770 





1908 


1040 




2 


NA 


NA 


NA 


10 


194 


MA 


12 354 


NA 


13 


566 


375 


18 


831 


510 


21 


1155 


^700 


25 


1536 


935 




5 


NA 


NA 


NA 


26 


189 


NA 


33 347 


NA 


40 


557 


369 


52 


820 


504 


60 


1141 


-692 


71 


1519 


926 




10 


NA 


NA 


NA 


33 


182 


MA 


43 335 


NA 


53 


542 


361 


68 


801 


493 


80 


1118 


":679 


94 


1492 


910 




15 


NA 


NA 


'NA 


40 


174 


NA 


50 321 


NA 


62 


528 


353 


80 


782 


482 


93 


1095 


f.666 


109 


1465 


895 




20 


NA 


NA 


NA 


47 


166 


NA 


59 311 


NA 


71 


513 


344 


90 


763 


471 


105 


1073 


•■653 


122 


1438 


880 




30 


NA 


NA 


NA 


NA 


NA 


NA 


78 290 


NA 


92 


483 


,NA 


115 


726 


449 


131 


1029 


•627, 


149 


1387 


849 




50 


NA 


NA 


NA 


NA 


NA 


NA 


NA NA 


NA 


147 


428 


NA 


180 


651 


405 


197 


944 


-575' 


217 


1288 


7871 



130 



CHIMNEYS AND VENTS 



Table 8-5 continued 



Table 8-5 [NFFA 54:Table 13.1(a)] Continued 



Number of Appliances: 



Appliance Type: 



Appliance Vent Connection: 



Single 



Category I 



Connected Directly to Vent 



















Vent Diameter — D (in.) 


















10 12 14 16 


18 


20 




22 24 




Appliance Input Rating 


in Thousands of Btu per Hour 




Heigh 
H 


t Latera 
L 

(ft) 


FAN 


Max 


FAN 


kAT 


FAN 


NA1 

M^ 


FAN NAl 
Min Max mS 


FAN NAl 
Min Max Max'' 


FAN 
Min Max 


3 

Ma; 


FAN NAT 
Min Max Mav 


FAN \ \ 1 
Min Max \1 1» 


(ft) 


MinMax 


MinMax 


MinMax 


6 





1121 


570' 


1645 1850 


2267 liiyo* 


2983 


islo 


3802 1960 





4721 


'243^ 





5737 


2*950 


6853 




2 


75 675 


455, 


103 982 650 


138 1346 890'. 


178 1769 


ii5;o 


225 2250 !1480 


296 


2782 


360 


3377 


?77'n' 


426 4030 




4 


110 668 


435> 


147 975 .640 
171 967 i630: 


191 1338 880,' 


242 1761 


1160 


300 2242 .1475 


390 


2774 


fS 


469 


3370 


[221S 


555 4023 




6 


128 661 


219 1330 ,870.' 


276 1753 


1150 


341 2235 1 1470 


437 


2767 


523 


3363 


221^ 


618 4017 


8 





1261 


66p| 


1858 m\ 


2571 


132§ 


C 3399 


174C 
i340 


4333 ;222b 





5387 


2U0 





6555 


336? 
253^ 


7838 - 




2 


71 770 


5\5i 


98 1124 745j 


130 1543 


1026j 


168 2030 


212 2584 |l700 


278 


3196 


336 


3882 


401 4634 




5 


115 758 


'm 


154 1110 73% 


199 1528 'lOfo' 


251 2013 


11330 


311 2563 ;i685 


398 


3180 


2090 
2070 


476 


3863 


562 4612 




8 


137 746 


180 1097 72d''' 


231 1514 ilOO'tf 


289 2000 


132(3 


354 2552 ;i670 


450 


3163 


537 


3850 


630 4602 


10 





1377 


ni 


2036 ;1060' 


2825 [1450 


3742 


1925 


4782 '2450 





5955 


305Q 





7254 


3710 


8682 




2 


68 852 


5601 


93 1244 jSSO- 


124 1713 11130 


161 2256 


'1480 


202 2868 'l890"' 


264 


3556 


'2346 
23*'' 


319 


4322 


2540 


378 5153 




5 


112 839 


m 


149 1229 !829-, 


192 1696 11105. 


243 2238 


146,1 


300 2849 '1871 


382 


3536 


458 


4301 


>2780 


540 5132 




10 


142 817 


5251 


187 1204 


795'' 


238 1669 


108^ 


298 2209 


1430 


364 2818 ,1840 


459 


3504 


2280^ 


546 


4268 


641 5099 


15 



2 


1596 
63 1019 


67| 


2380 
86 1495 


1240 
985' 


3323 
114 2062 


'I35q 


4423 
147 2719 


2270 
1770 


5678 '2900 
186 3467 ■22'60' 



239 


7099 
4304 


28(| 

27!^ 

2700 



290 


8665 
5232 


'^85; 

33^ 


10393 
346 6251 




5 


105 1003 


660j< 

635* 


140 1476 


-96:^5 


182 2041 132?, 


229 2696 


1748 
1712 


283 3442 ;2235' 


355 


4278 


426 


5204 


501 6222 




10 


135 977 


177 1446 


936i: 


227 2009 flM 


283 2659 


346 3402 [2193 


432 


4234 


510 


5159 


599 6175 




15 


155 953 t610| 


202 1418 '905': 


257 1976 llTSO 


318 2623 1675' 


385 3363 -2150 


479 


4192 


564 


5115 


3300 


665 6129 


20 



2 


1756 
59 1150 


930" 


2637 aSSg 
81 1694 hppj 


3701 il9'dq' 
107 2343 1525, 


4948 252d 
139 3097 MQ^ 


6376 [3250 
175 3955 2570 



220 


7988 
4916 


4060j 

31^1 



269 


9785 
5983 


3W 


11753 
321 7154 




5 


101 1133 


7.3& 


135 1674 '107^ 


174 2320 1498' 
220 2282 146^ 
248 2245 |l4;^ 


219 3071 wfl 


270 3926 12544, 


337 


4885 


403 


5950 


1 


475 7119 




10 

15 


130 1105 
150 1078 


^i 

m 


172 1641 P,45 
195 1609 ioif 


273 3029 im 
306 2988 1910 


334 3880 12500' 
372 3835 ,2465 


413 
459 


4835 
4786 


s? 


489 

541 


5896 
5844 


573 7063 
631 7007 




20 


167 1052 ^6W> 


217 1578 i 990l 


273 2210 11390 


335 2948 1880 


404 3791 2430* 


495 


4737 


585 


5792 


3760, 


689 6953 


30 





1977 w'eo, 


3004 J155D' 


4252 i2170. 


5725 S2920 
127 3696 psS 


7420 3770 





9341 


„ 'S 
4750t 





11483 


'5850 


13848 




2 


54 1351 


865'» 


74 2004 


13"10 


98 2786 1800 


159 4734 >3050 


199 


5900 


38lrf 
3781. 


241 


7194 


465tf 


285 8617 




5 


96 1332 


8511 


127 1981 


1289 


164 2759 (175^. 


206 3666 23^' 


252 4701 ;3020 


312 


5863 


373 


7155 


4622 


439 8574 




10 


125 1301 


829} 


164 1944 11254 
187 1908 122(1 


209 2716 il'^l 


259 3617 ^3* 


316 4647 52970 


386 


5803 


374 


456 


7090 


4574- 

to?? 


535 8505 




15 


143 1272 


8O7J 


237 2674 ife 


292 3570 J22'50 
319 3523 mp 
369 3433 gisj 


354 4594 }2920 


431 


5744 


Sms^ 


507 


7026 


590 8437 




20 


160 1243 


78^ 


207 1873 118| 
246 1807 jli'sO 


260 2633 ihM 


384 4542 J2870, 


467 


5686 


3650) 


548 


6964 


639 8370 




30 


195 1189 


74S 


305 2555 tlbsl 


440 4442 j2785; 


540 


5574 


356^ 


635 


6842 


739 8239 


50 





2231 


il95, 


3441 (1825 


4934 2550 


6711 kMa 


8774 !4460" 





11129 


5635" 





13767 694), 


16694 




2 


41 1620 lOigl 


66 2431 11513 


86 3409 212^ 


113 4554 pSid 
191 4520 2813 


141 5864 '3670 


171 


7339 


4630: 


209 


8980 6fe95 


251 10788 




5 


90 1600 


9965 


118 2406 (mi 


151 3380 ;2102 


234 5826 3639 


283 


7295 


459:7; 


336 


8933 15654 


394 10737 




10 


118 1567 


9721 


154 2366 


'1466 


196 3332 [206^ 
222 3285 Si026' 


243 4464 2767 


295 5763 '3585 


355 


7224 


45i2 


419 


8855 


5385^ 


491 10652 




15 


136 1536 


9481 


177 2327 


I4S7, 


274 4409 2721 


330 5701 !3534, 


396 


7155 


4511f 


465 


8779 


55^ 


542 10570 




20 


151 1505 


5241 


195 2288 


140^ 


244 3239 


i987' 


300 4356 ^675 


361 5641 '348f 


433 


7086 


4479' 
4421! 


506 


8704 


0> 
'5444 


586 10488 ' 




30 


183 1446 


876'' 


232 2214 


1349 


287 3150 


1910. 


347 4253 S2631. 


412 5523 i3431 


494 


6953 


577 


8557 


672 10328 


100 





2491 


1^ 
310, 


3925 


i05Q 


5729 


2950 


7914 ko50 
95 5834 8500 
172 5797 |3475 


10485 |5300 





13454 


5 • 
6700' 





16817 


7200 


20578 




2 


30 1975 1170] 


44 3027 


1820' 


72 4313 


2550 


120 7591 14600 


138 


9577 


58I34 


169 


11803 


204 14264 




5 


82 1955 ^159] 


107 3002 1803 


136 4282 


2531; 


208 7548 4566 


245 


9528 


57^Sf 


293 


11748 


7162' 


341 14204 




10 


108 1923 1142 


142 2961 


1775 


180 4231 12500 


223 5737 3434 


268 7478 .4509 


318. 


9447 


571^' 


374 


11658 


7100 


436 14105 




15 


126 1892 1 




163 2920 


1747 


206 4182 ;2469^ 
226 4133 2438 


252 5678 ^392 
277 5619 B3S1 


304 7409 '«51 


358 


9367 


5665, 


418 


11569 


7037, 


487 14007 




20 


141 1861 1 


181 2880 


1719 


330 7341 '4394 


387 


9289 


5613. 


452 


11482 


6975' 


523 13910 




30 


170 1802 11 


071 


215 2803 


1663 


265 4037 2375'' 


319 5505 b267 


378 7209 (4279 


446 


9136 


5509' 


514 


11310 


6850 


592 13720 




50 


241 1688 1 


000' 


292 2657 t 


1550" 


350 3856 2250 


415 5289 3100 


486 6956 [4050 


572 


8841 


5300. 


659 


10979 


6600 


752 13354 



131 



Table 8-6 



2007 CALIFORNIA MECHANICAL CODE 



Table 8-6 Type B Double-Wall Vent with Single Appliance and Single-Wall Metal Connector [NFPA 54:Table 13.1(b)] | 





Number of Appliances: 


Single 




Appliance Type: 


Category I 




Appliance Vent Connection: 


Single-Wall Metal Cormector 



Vent Diameter — D (in.) 





Lateral 


3 


4 


5 




6 


7 




8 






9 




10 




12 


















Appliance 


^JhiputB 


Latit 


g-in 


Thousands of 


Btu per H 


our 










Heigh 


( 








-. 




] 


H 


L 

(ft) 


FAN S(AT 


FAN NAT 
Min Maxlitoc 


FAN , 
MinMax 


NAT 

f ■ ■ 
TMax 


FAN 
Min Max 


<rAT 

ISlax 


FAN 
MinMax 


NAT 

Max 


FAN 
MinMax 


NAT 
Max 


FAN 
MinMax 


NAT 
:Max 


FAN 
MinMax 


Stat 

'Max 


Mm Mix 


vat' 


(ft) 


I. 
Mill MaxMax 


1 

Mi\l 


6 





38 77F45 


59 


151 


?65 


85 


249 


8140 


126 


373 


»204 


165 


522 


,284 


211 


695 


,369 


267 894 


•■469 


371 1118 


'^69 


53- liv" 


.•^ ' 




2 


39 51 pe 


60 


96 


he 


85 


156 


ao4 


123 


231 


m6 


159 


320 


to 


201 


423 


;2S4 


251 541 


'368 


347 673 


T4S3 


498 979 


643 




4 


NANApS 


74 


92 


"63 


102 


152 


«102 


146 


225 


i:i52 


187 


313 


'208 


237 


416 


I277 

271 


295 533 


i:360 


409 664 


;443 


584 971 


-638 




6 


NANA ^31 


83 


89 


?60 


114 


147 


E§9 


163 


220 


S148 


207 


307 


^203 


263 


409 


327 526 


-352 


449 656 


433 


638 962 


627 


8 





37 83 IsO 


58 


164 


& 


83 


273 


|54 
!l19 


123 


412 


li'79 


161 


580 


-319 


2C6 


777 


'414 


258 1002 


* 
'536 


360 1257 


%5S 


521 1852 


967! 




2 


39 56 :-39 


59 


108 


:^75 


83 


176 


121 


261 


155 


363 


246 


197 


482 


:-321 


246 617 


,417 


339 768 


-513 


486 1120 


'743 




5 


NANAB37 
NANA ^33 


77 


102 


E69 


107 


168 


'kt)7 


151 


252 


*r63 


193 


352 


.235 


245 


470 


.311 


305 604 


,-404 


418 754 


;soo 


598 1104 


,730 




8 


90 


95 


'M 


122 


161 


175 


243 


223 


342 


1225 


280 


458 


■300 


344 591 


-'392 


470 740 


-'486 


665 1089 


.715 


10 





37 87 ?53 
39 6l|'4) 


57 


174 


^99 


82 


293 




120 


444 


■:isi 


158 


628 


"sk 


202 


844 


'449 


253 1093 


-584 


351 1373 


^718 


507 2031 1057 




2 


59 


117 


"80 


82 


193 


H28 


119 


287 


;'i94 


153 


400 


'272 


193 


531 


■354 


242 681 


''456 


332 849 


559 


475 1242 


848 




5 


52 56 g39 • 
NANAC34 


76 


111 


fc76 


105 


185 


1122. 


148 


277 


*-186 


190 


388 


.261 


241 


518 


.344 


299 667 


*443 


409 834 


i-S44 


584 1224 


825 




10 


97 


100 


f.68 


132 


171 


hl2 


188 


261 


-1-71 


237 


369 


an 


296 


497 


325 


363 643 


^"423 


492 808 


2520 


688 1194 


-788 


15 





36 93 5-57 


56 


190 


\ll 


80 


325 


S86 


116 


499 


€283 


153 


713 


388 


195 


966 


'523 


244 1259 


r681 


336 1591 


^838 


488 2374 


1237 




2 


38 69 ^47 


57 


136 


■93 


80 


225 


•jiis 


115 


337 


1^224 


148 


473 


;314 


187 


631 


'413 


232 812 


543 


319 1015 


.-'673 


457 1491 


■983 




5 


51 63 ;.p. 


75 


128 


:86 


102 


216 


pi40 


144 


326 


1217 


182 


459 


^298 


231 


616 


.'400 


287 795 


;S26 


392 997 


.^657 


562 1469 


963' 




10 


NANA ^39 


95 


116 


179 


128 


201 


|31 
|24 


182 


308 


S03 


228 


438 


p84 


284 


592 


381 


349 768 


^«1 
l84 


470 966 


i&8 


664 1433 


-'928 ; 




15 


NANApNA 


NA 


NA 


!.72 


158 


186 


220 


290 


^.'92. 


272 


418 


;2(59 


334 


568 


;367 


404 742 


540 937 


feoi 


750 1399 


;'894 '■ 


20 





35 96 *60 


54 


200 


|6" 

^18 


78 


346 


loi 

|65 


114 


537 


|06 


149 


772 


428 


190 


1053 


W.3 


238 1379 


•750 


326 1751 


027 


473 2631 


'1346' 




2 


37 74 ^50 


56 


148 


S99 


78 


248 


113 


375 


i.i248 


144 


528 


>344 


182 


708 


him 


227 914 


■"611 


309 1146 


£-754 


443 1689 


1098! 




5 


50 68 ^47 


73 


140 


m- 


100 


239 


«15~8 


141 


363 


I239 


178 


514 


P* 


224 


692 


■457 


279 896 


;:596 


381 1126 


t734 


547 1665 


1074 




10 
15 


NANA J41 
NANA%A 


93 
NA 


129 
NA 


'86 

•80 


125 
155 


223 
208 


:»6 

;135 


177 
216 


344 
325 


feo 


222 
264 


491 
469 


i316 
'301 


277 
325 


666 
640 


r-437 
419 


339 866 
393 838 


;570 
'549 


457 1092 
526 1060 


-702 
1677 


646 1626 
730 1587 


1037 
•1005. 




20 


nanaFna 


NA 


NA 


i;NA 


186 


192 


i.126 


254 


306 


•i-'S96 


309 


448 


■285 


374 


616 


'400 


448 810 


■5526 


592 1028 


'651 


808 1550 


973 


30 





34 99^63 
37 80p56 


53 


211 


327 


76 


372 


% 


110 


584 


>334' 


144 


849 


472 


184 


1168 


■647 


229 1542 


;852 


312 1971 


-1056 


454 2996 


1545. 




2 


55 


164 


•111 


76 


281 


im 


109 


429 


"279 


139 


610 


•392 


175 


823 


.533 


219 1069 


■698 


296 1346 


863 


424 1999 


1308. 




5 


49 74 h52 


72 


157 


.106 


98 


271 


ii73 


136 


417 


.271 


171 


595 


.382 


215 


806 


;521 


269 1049 


1.684 


366 1324 


!t846 


524 1971 


.1283. 




10 


NANA ^A 


91 


144 


Sgs 


122 


255 


iM8 

Ia 


171 


397 


•257 


213 


570 


f367 


265 


777 


■SOI 


327 1017 


-662 


440 1287 


%21 


620 1927 


1243 




15 


NANA INA 


115 


131 




151 


239 


208 


377 


;.242 


255 


547 


'■349 


312 


750 


(■481 


379 985 


te8 


507 1251 


p4 
3.768 


702 1884 


1205 




20 


NANA 'NA 


NA 


NA 


Mk 


181 


223 


246 


357 


!I228 


298 


524 


;333 


360 


723 


■461 


433 955 


i615 


570 1216 


780 1841 


1166' 




30 


NANA llSIA 


NA 


NA 


■m 


NA NA 


NA 


NA 


,^A 


389 


477 


'305 


461 


670 


';'426 


541 895 


m 


704 1147 


i720 


937 1759 


1101 


50 





33 99 i66 


51 


213 


h 


73 


394 


;230 


105 


629 


361 


138 


928 


Sis 

=443 


176 


1292 


s- ■ 

.704 


220 1724 


'ms 


295 2223 


■(189 


428 3432 


1818, 




2 


36 84 hil 


53 


181 


\X11 


73 


318 


'205 


104 


495 


.-312 


133 


712 


168 


971 


1613 


209 1273 


■811 


280 1615 


1007 


401 2426 


1509: 




5 


48 80 ^A 


70 


174 


117 


94 


308 


fl98 
■'186 


131 


482 


?305 


164 


696 


tes 


204 


953 


6602 


257 1252 


,':795 


347 1591 


b9i 


496 2396 


1490 




10 


NANA CNA 


89 


160 


NA 


118 


292 


162 


461 


.292 


203 


671 


f420 


253 


923 


i583 


313 1217 


'765 


418 1551 


;.?63 


589 2347 


1455 




15 


NANA 5^A 


112 


148 


NA 


145 


275 


■;iL74 


199 


441 


= 280 


244 


646 


t"405 


299 


894 


562 


363 1183 


:.736 


481 1512 


,934 


668 2299 


11421 




20 


NANA fNA 


NA 


NA 


NA 


176 


257 


'NA 


236 


420 


;'267 


285 


622 


.389 


345 


866 


-543 


415 1150 


708 


544 1473 


,906 


741 2251 


1,1387 




30 


NANA ,NA 


NA 


NA 


■^A 


NA NA 


»A 


315 


376 


•ISIA 


373 


573 


LNA 


442 


809 


502 


521 1086 


;,649 


674 1399 


,;84a 


892 2159 


1318' 


100 





NANA^JA 
NANApA 


49 


214 


NA 


69 


403 


fNA - 


100 


659 


395 


131 


991 


^555 
■5O8 


166 


1404 


■-765 


207 1900 


.1033 


273 2479 


1300 


395 3912 


2042' 




2 


51 


192 


■NA 


70 


351 


98 


563 


:373 


125 


828 


158 


1152 


:698 


196 1532, 


',933 


259 1970 


t;ii68 


371 3021 


1817, 




5 


NANA &IA 


67 


186 


jNA 


90 


342 


m 


125 


551 


'366 


156 


813 


'501 


194 


1134 


688 


240 1511 


'921 


322 1945 


1153 


460 2990 


1796 




10 


NANA ,t^A 


85 


175 


»A 


113 


324 


m' 


153 


532 


!354 


191 


789 


'486 


238 


1104 


"672 


293 1477 


-;902 


389 1905 


1133 


547 2938 


1763 




15 


NANA ^l^A 


132 


162 


bJA 


138 


310 


■NA 


188 


511 


?343 


230 


764 


'473 


281 


1075 


>656 


342 1443 


^884 


447 1865 


lllO 


618 2888 


1730 




20 


NANA i'A 


NA 


NA 


nh 


168 


295 


Wa 


224 


487 


;'Na 


270 


739 


458 


325 


1046 


639 


391 1410 


E864 


507 1825 


1087 


690 2838 


1696 




30 


NANA SNA 


NA 


NA 


MA 


231 


264 


rNA 


301 


448 


NA 


355 


685 


•NA 


418 


988 


:NA 


491 1343 


*824 


631 1747 


rl041 


834 2739 


1627 




50 


NANAiNA 


NA 


NA 


NA 


NA NA 


!NA 


NA 


NA 


:t^A 


540 


584 


'NfA 


617 


866 


NA 


711 1205 


-NA 


138 1591 


-NA 


1138 2547 


1489 



132 



CHIMNEYS AND VENTS 



Table 8-7 



Table 8-7 Masonry Chimney with Single Appliance and Type B Double- Wall Connector [NFPA 54:Table 13.1(c)] | 





Number of Appliances: 


Single 




Appliance Type: 


Category I 




Appliance Vent Connection: 


Type B Double-Wall Connector 

















Type B Double-Wall Connector Diameter — D (in.) 










tLatera 
L 

(ft) 


To be used with chimney areas within the size limits at bottom 




3 1 4 Is 1 6 


1 7 


Is 1 9 1 10 1 12 


Heigf 
H 

(ft) 


FAN 
MinMax 


NAl 
Max 


1 ■" 

FAN NAT 

1 » J 

Min Max 'Max 


Ap 

FAN ISfAT 
Min Max Max 


^liance 

FAN 

MinMax 


Input Rating in " 

NA'r FAN jSTAl 
iMa'x Min Max 'Max 


rhousands of Btu per Hour 

rwi •" -Z f"^ r -'im 
FAN INAT fan ^AT fan NAl FAN NA-T- 

MinMax iMa» Min Max'Ma)^' Min MaxjMax Min Max 'Max^ 


6 


2 


NANAf 28^' 


NA NA ! 52'.; 


NANA 86' 


NANA 1130- 


NA NA 


'l80. 


NA NA ;247:,' 


NA NAi 320 


NA NA|401i'' 


NA NA ^58'S 
NA NA.5611 




5 


NANA 


25i 


NA NA . 4§ - 


NA NA §1', 


NANA 


117^ 


NA NA 


165 


NANA. 231 j. 


NA NA 12981 


NA NA'376» 


8 


2 


NANA 


29'^ 


NANA 55^J 


NA NA -m 


NANA 


ii5<. 


NA NA 


198 


NANA 


m 


84 590f35.0? 


100 728 


446 


139 1024:65^ 




5 


NANA 


-26s 
24- 


NANA[S2f 


NANA 88i 


NANA 


134'; 


NA NA 


183' 

'175; 


NANA 


24:5 


NA NA 328| 


149 711 


423 


201 1007 > 64^ 




8 


NANA 


NA NA 1 48; 


NANA! 83 J 


NANA 


127 


NA NA 


NANA 


.239J 


NA NA sis! 


173 695!4l'0-; 


231 990 ' 6231 


10 


2 


NANA 


'Sii 


NA NA [ 61 


NANA ioS". 


NANA 


162- 


NA NA 


22tf 


68 519 


'298? 


82 655 [388^ 


98 810 49i: 


136 1144.72! 




5 


NANA 


28., 


NANA 57' 


NA NA 96! 


NANA 


148: 


NA NA 


204 


NANA 277-. 


124 638'365| 


146 791 466, 


196 1124; 71^ 




10 


NANA 


25 


NA NA I 50*: 


NA NA '87 


NANA 


139 


NA NA 


191' 


NANA 263' 


155 610-347 


182 762 444 


240 1093 ' 6683 


15 


2 


NANA 


35-' 


NA NA 'f 67 


NA NA ui 


NANA 


1 179' 


53 475 


250^ 


64 613 iisel 


77 779 '441; 


92 968 156^' 


127 1376; 841^ 




5 


NANA 


35- 


NANAJ62': 


NA NA 107 


NANA 


.■164' 


NA NA 


231 


99 594 [3% 


118 759 1416; 


139 946(533^ 


186 1352 (828| 




10 


NANA .28:6 


NANA I 55': 


NANA 


9Z<-. 


NANA 


,153^ 


NA NA 


2i6'. 


126 565 2?fe 
NANA ■Zk-I 


148 727 [3,94} 


173 912 567^ 


229 13] 5 17#'| 




15 


NANA NAt 


NANA 48'-^ 


NANA 


89^ 


NANA 


141i 


NA NA 


201' 


171 698^75,' 


198 880 485: 


259.1280. 7l2i 


20 


2 


NANAJ 38', 


NANA 74'^ 


NANA 


'l24' 


NANA 


■2oi| 


51 522 


2^741 


61 678 .375| 


73 867f49l,l 


87 1083j627:' 
133 1059 597i 


121 1548 1 95i 




5 


NANA 


36" 


NA NA [ 68i. 


NANA 


11,6 


NANA 


-184' 


80 503 


254'. 


95 658 350.. 


113 845 463'. 


179 1523 ' 933 




10 


NANA 


NA-' 


NA NA , 60, 


NANA 


► 107 


NANA 


172-. 


NA NA 


237 


122 627 


332' 


143 811 AO , 


167 1022.566- 


2211482 879,| 




15 


nana'na. 


NA NA ;NA 


NA NA' 97 


NANA 


159 


NA NA 


220' 


NANA 


314,- 


165 780 1 418- 


191 987 541, 


25ri443j840{ 




20 


nanaIisia: 


NA NA ,NA. 


NA NAi 83' 


NANA 


148 


NA NA 


206. 


NANA 296 


186 750;397,, 


214 9551513: 


277 1406* 8071 


30 


2 


NANA 


. 41-; 


NANA 82.-' 


NA NAf-137. 


NANA 


216, 


47 581 


303 


57 762 


42te 


68 985r558,' 
106 962 526', 


81 1240*717-. 


111 1793 illl 
169 1766 ;iO,^l 




5 


NANA 


NA. 


NANA ,76,, 


NA NA 128 


NANA 


19g; 


75 561 


281- 


90 741 


393f 


125 1216[6§3' 




10 


NANA 


NA'- 


NANA '67,i 


NA NA 115, 


NANA 


■"184, 


NA NA 


263: 


115 709 


373'i, 


135 927rg00j; 


158 1176!648. 


210 1721 iio'ii 




15 


NANA 


NA« 


NA NA (NA!* 


NA NA 107; 


NANA 


'171,^ 


NA NA 


24$ 


NANA 


353^ 


156 893;476j 


181 1139 621i 


239 1679:983 




20 


NANA NA- 


NANA; NX 


NA NA[ 91, 


NANA 


15§ 


NA NA 


227 


NANA 


332; 


176 860 1 450, 


203 1103592' 


264 1638 )940J 




30 


NANA NA 


NA NA iNA 


NA NA NA 


NANA 


NA" 


NA NA 


188 


NANA 


288'-; 


NA NA,416- 


249 1035555. 


318 156018771 


50 


2 


NANA 


NA- 


NA NA ' 92 


NA NA 1^1 


NANA 


251. 


NA NA 


351, 


51 840 


47^r 


61 1106.633' 


72 1413 812 


99 2080,1243^ 




5 


NANA 


NA, 


NA NA fNA 


NA NA 15,1 


NANA 


230. 


NA NA 


323 


83 819 


445i; 


98 1083.596 


116 1387[77^ 


155 2052 ;1?75j 
195 2006 11145 




10 


NANA 


NA-. 


NANA NA. 


NA NA 138 


NANA 


215 


NA NA 


304, 


NANA 424f 
NANA 40q^ 
NANA l376> 


126 1047-5P,, 


147 1347i733J 




15 


NANA 


NAi 


NA NA N4, 


NANAtl27 


NANA 


199, 


NA NA 


282. 


146 1010 53?; 


170 1307|7J!2| 
190 1269^6^1 


222 1961 ;109| 




20 


NANA 


NA'. 


NA NA NA' 


NANAiNA 


NANA 


185, 


NA NA 


264 


165 977 511J= 


246 1916 ,'1050, 
295 1832 -'981 




30 


NANA 


NA 


NA NA NA' 


NA NaInA 


NANA 


NA'. 


NA NA 


MA' 


NANA '3271 


NA NA 468'^ 


233 1196(623! 


Minimum 
Internal Area 
of Cliimney 


12 


19 


28 


38 




50 




63 


78 


95 


132 


(Square 


Inches) 
























Maximum 
























Internal Area 
























of Chimney 
(Square Inches) 


49 


88 


137 


198 




269 




352 


445 


550 792 



133 



Table 8-8 



2007 CALIFORNIA MECHANICAL CODE 



Table 8-8 Masonry Chimney with Single Appliance and Single-Wall Metal Connector [NFPA 54:Table 13.1(d)] 



Number of Appliances: 



Appliance Type: 



Appliance Vent Connection: 



Single 



Category I 



Single-Wall Metal Connector 



Single-Wall Metal Connector Diameter — D (in.) 
To be used with chimney areas within the size limits at bottom 



10 



12 



Height Later il 

H L 

(ft.) (ft.) 



Appliance Input Rating in Thousands of Btu per Hour 



FAN 



Min Max Max 



fan: 



Min Max |] 



FAN NAT 
Min Max JMax 



FAN NAT 



Min Max ||>^ax 



FAN NAT 



Min Max tMax 



FAN 



w 



Min Max iMax 



(7- 
FAN NAT 



Min Max Max 



FAN NAT 



Min Max Max 



FAN 

Min Max 



NAT 
Max, 



NA NA 
NA NA |2S 



NA NAi 
NA NaI 



NA NA 
NA NA 



NA NA M30 
NA NA & 



NA 
NA 



NA MO 
NA 1.64 



NA NA |247 
NA NA IzSb 



NA NA |819 
NA NA 1297 



NA NA poo 

NA NA fe75 



NA NA 
NA NA 



:.580 
$60 ■ 




NA NA 
NA NA 
NANA 




NA NA E45 
NA NA K33 
NA NA E26' 



NA 
NA 
NA 



NA ^197 

NA ik 

NA ra74 




NA NA g49 
NA NA fe27 
NA NA &i7 




549 1021 
673 1003 
747 985 



650 1 
:638 ■ 
621 





NA NA & 
NA NA mS 
NA NA isb 




NA 
NA 
NA 



NA pO 

NA 203 

Si- 
NA B:89 



216 518 p97 
NA NA p76 
NA NAb61 



271 654 g87 
334 635 p64 
NA NA 1345 



373 808 B?P 
459 789 M65 
547 "" ■"■'•' 



536 1142 
657 1121 
771 1088 



722 
'710 ' 
665 ' 






NA NA 



NA NA 6178 

NA NA |i63 

NA NA M51 

NA NA il38 



166 

NA 
NA 
NA 



473 t249 

NA ^0 

NA fei4 

NA im 



211 611 |335 

261 591 |312 

NA NA 1594 

NA NAK78 



264 776 

325 755 pl4 

392 722 S^l 

452 692 &2 



362 

444 

531 yu/ purt 

606 873 Ml 



520 1373 

637 1348 

749 1309 

841 1272 



-825 , 
,774 

^8' 



20 





NA NA 
NA NA i.15 
NA NA POS 
NA NA 
NA NA 



NA NA Boo 

NA NA i.83 

NA NA M.70 

NA NA p56 

NA NA |l44 




206 675 p74 

255 655 P48 

312 622 p30 

NA NA pil 

NA NA I292 



258 864 p?0 

317 842 g61 

382 806 p7 

442 773 gi4 

NA NA B92 



252 1079 [625 

433 1055 hsi 

517 1016 hSX 

591 979 ms 

663 944 [510 



508 1544 

623 1518 

733 1475 

823 1434 

911 1394 



f950| 

^30' 

;875 , 



NA NA 

NA NA NA 
NA NA |rA 
NA NA pA 
NA NA 
NA NA iTA 



NANA 




NA NA 
NA NA B27 

NA NA iaa 

NA NA B05 
NA NA 
NA NA KA 



NA NA pl5 

NA NA |i96 
NA NA il'82 
NA NA B68 
NA NA E55 
NA NA RA 



578 f3,02 




200 759 |420 

245 737 1391 

300 703 1370 

NA NA |34S 

NA NaII?? 

NA NA& 



249 982 |556 

306 958 ||24 

370 920 \m 

428 884 671 

NA NA K5 

NA NA &• 



340 1237 

417 1210 K80 

500 1168 |644 

572 1128 feiS 

643 1089 

NA NA [S44 



489 1789 

600 1760 
708 1713 
798 1668 
883 1624 
1055 1539 



1110' 
1090, 

;|020 

'§75 ' 



932; 



■8ffi 



50 2 

5 
10 
15 
20 

30_ 

Minimum 
Internal Area of 
Qiinmey 
(Square Inches) 

Maximum 
Internal Area of 
Ounuiey 
(Square Inches) 





12 



49 



19 



NA NA K60 
NA NA 
NA NA |i36 
NA NA [124 
NA NA fNA 
NA NA [NA 

28 



137 



NA NA K50 
NA NA I228 
NA NA 
NA NA 
NA NA 
NA NA 




38 



198 



50 



269 



191 837 ||75 

NA NA 1442 

NA NA t420 

NA NA .395 

NA NA [ 370 

NA NA P318 

63 



352 



238 1103 

293 1078 S593 

355 1038 1562 

NA NA p33 

NA NA f 504 

NA NA 

78 



445 



323 1408 fSlO 

398 1381 p70 

447 1337 [728 

546 1294 ms 

616 1251 1660 

NA NA (610 

95 



550 



463 2076 J240' 
571 2044ft2201 
674 19941J40; 
761 1945? 
844 1898; 
1009 180 5 

132 



792 



3, 
IXi 

1090 

1040 

970 



134 



CHIMNEYS AND VENTS 



Table 8-9 



Table 8-9 Single-Wall Metal Pipe or Type B Asbestos Cement Vent with Single Appliance [NFPA 54:Table 13.1(e)] I 













Number of Appliances: 


Single 




Appliance 


Type: 




Draft Hood-Equipment 




Appliance 


Vent Connection: 


Connected Directly to Pipe or Vent 










Diameter - D (in.) 












To be used with chimney area 


within the size limits at bottom 








Lateral 
L 


3 


4 


5 


6 


7 


8 


10 


12 


Height 


Appliance Input Rating in Thousands of Btu per Hour 


H 
















(ft) 


(ft) 




Maximum Appliance Input Rating in Thousands of Btu per Hour 




6 





39 


70 


116 


170 


232 312 


500 


750 




2 


31 


55 


94 


141 


194 260 


415 


620 




5 


28 


51 


88 


128 


177 242 


390 


600 


8 





42 


76 


126 


185 


252 340 


542 


815 




2 


32 


61 


102 


154 


210 284 


451 


680 




5 


29 


56 


95 


141 


194 264 


430 


648 




10 


24 


49 


86 


131 


180 250 


406 


625 


10 





45 


84 


138 


202 


279 372 


606 


912 




2 


35 


67 


111 


168 


233 311 


505 


. 760 




5 


32 


61 


104 


153 


215 289 


480 


724 




10 


27 • 


54 


94 


143 


200 274 


455 


700 




15 


NA ' 


46 


.84 


130 


186 258 


432 


666 


15 





49 


91 


151 


223 


312 420 


684 


1040 




2 


39 


72 


122 


186 


260 350 


570 


865 




5 


35 


67 


110 


170 


240 325 


540 


825 




10 


30 


58 


103 


158 


223 308 


514 


795 




15 


NA 


50 


93 


144 


207 291 


488 


760 




20 


NA 


NA 


82 


132 


195 273 


466 


726 


20 





53 


101 


163 


252 


342 470 


770 


1190 




2 


42 


80 


136 


210 


286 392 


641 


990 




5 


38 


74 


123 


192 


264 364 


610 


945 




10 


32 


65 


115 


178 


246 345 


571 


910 




15 


NA 


55 


104 


163 


228 326 


550 


870 




20 


NA 


NA 


91 


149 


214 306 


525 


832 


30 





56 


108 


183 


276 


384 529 


878 


1370 




2 


44 


84 


148 


230 


320 441 


730 


1140 




5 


NA 


78 


■137 


210 


296 410 


694 


1080 




10 


NA 


68 


125 


196 


274 388 


656 


1050 




15 


NA 


NA 


113 


177 


258 366 


625 


1000 




20, 


NA 


NA 


99 


163 


240 344 


596 


960 




30 


NA 


NA 


NA 


NA 


192 295 


540 


890 


50 





NA 


120 


210 


310 


443, 590 


980 


1550 




2 


NA 


95 


171 


260 


370 492 


820 


1290 




5 


NA 


NA 


159 


234 


342 474 


780 


1230 




10 


NA 


NA 


146 


221 


318 456 


730 


1190 




15 


NA 


NA 


NA 


200 


292 407 


705 


1130 




20 


NA 


NA 


NA 


185 


276 384 


670 


1080 




30 


NA 


NA 


NA 


NA 


222 330 


605 


1010 



135 



Table 8-10 



2007 CALIFORNIA MECHANICAL CODE 



Table 8-10 Type B Double-Wall Vent with Two or More Appliances and Type B Double-Wall Connector 



I [NFPA 54:Table 13.2(a)] 



Number of Appliances: 



Appliance Type: 



Appliance Vent Connection: 



Two or More 



Category I 



Type B Double-Wall Connector 



Type B Double-Wall Vent and Connector Diameter — D (in.) 



6 



8 



10 



Height Rise 
H R 

(ft.) (ft.) 



FAN 



Min Mapl aai Min MayMa: :MinMa)^VIax. Vlin Max (Max MinMax ||Max Vlin Max 



Appliance Inpiut Rating in 



FAN pATi 



FAN m'AT 



Thousands of Btu per Hour 



FAN IjJXT 



FAN 



XT 



FAN mUT 



iMax 



FAN 



Min Max 



SIAT 
Max 



MinMaxlJdax 



FAN NAT 




35 
37 
38 



66|46 
75|55 
8l|62 



46 106 1, 72 

48 121 1 86 

49 132fr96 



58 164 |1,04 
60 183 p24 
62 199 039 



77 225E142 
79 253rd68 
82 2751-189 



92 296 
95 333 
97 363 



',185 

r^2o 

•:248 



109 376 
112 424 
114 463 



r237 
282 

:%i7 



128 466 
131 526 
134 575 



289 

l&45| 
3861 




35 72r48 

36 80|57 

37 8^.64 



49 114 p 76 
51 128 190 
53 I39I1OI 



64 176 |109 

66 195 |i29 

67 210 fe 



84 243|148 
86 269 p75 
88 290h'l98 



100 320 
103 356 
105 384 



^230 
'.'258 



118 408 
121 454 
123 492 



^248 
i294 
%30 



138 507 
141 564 
143 612 



303. 

;358 : 

402 



10 




34 
36 
37 



781-50 
set 59 
92- ''67 



49 123 f 78 

51 136|-~93 

52 146i*i04 



65 189 pl3 
67 206 H34 
69 220 rl50 



89 257ri54 
91 282 tl82 
94 303r-205 



106 341 
109 374 
111 402 



200 

238 

'.268 



125 436 
128 479 



-257 
;305 



131 515 ;342 



146 542 
149 596 
152 642 



314 
372 
417 



15 




33 
35 
36 



89| 53 
96^ 63 
102.71 



47 1421. 
49 153 1 
51 163 



64 
66 
68 



220 1 120 
235 h42 
248 &60 



88 298 163 
91 320 M93 
93 339fel8 



110 389 
112 419 
115 445 



'214 
:253 

::286 



134 493 
137 532 
140 565 



.273 
!323 
|365 



162 609 
165 658 
167 700 



333 

^94' 

444 



20 




33 
34 
35 



99p'56 
105' 66 
110^.74 



46 1571 
48 167 [ 
50 176 



62 
64 
66 



246 &25 
259 ll'49 
271 E68 



86 334 em 

89 354ra02 
91 371P228 



107 436 
110 463 
113 486 



■224 
265 
300 



131 552 
134 587 
137 618 



'285 

!:;339 

383 



158 681 
161 725 
164 764 



-347 ■ 
"414 
l66 , 



30 




31 
33 
34 



113" 59 
118, 70 
123-:79 



45 181 

47 190 

48 198 



ft ■ 

r-93 
bio 

W24 



60 
62 
64 



288 pi34 
299 |l58 
309 1178 



83 39ip:82 
85 408|215 
88 423K242 



103 512 
105 535 
108 555 



-238 

i-'317 



125 649 
129 679 
132 706 



r^SOS 
'1360 
v405 



151 802 
155 840 
158 874 



372 
439 
494 



50 




30 
32 
33 



133- 64 
13!S 76 
14i;' 86 



43 216fj-101 

45 223frll9 

46 229 L 134, 



57 
59 
61 



349 fl-45- 
358 H72 
366 |l94 



78 477^.97 
81 490 1234 
83 502 h.'263 



97 627 
100 645 
103 661 



257 
••306 
;343 



120 797 
123 820 
126 842 



•330 
.392 
^441 



144 984 
148 1014 
151 1043 



■403 
478 
538 



100 



18 82 

19 83 

20 84 



28 
30 
31 



158j;66 
16|79 
163''89 



40 262bl04 
42 267|l23 
44 2721138 



53 442 0.50 
55 447p.78 
57 452 KOO 



73 6111.204 
75 6I9I242 
78 627F272 



91 810 
94 822 
97 834 



ft266 
5316 

r355 



112 1038 
115 1054 
118 1069 



a3.41 
4405 
'MBS 



135 1285 
139 1306 
142 1327 



:417. 
.494' 

|555^ 



Common Vent Capacity 



Type B Double- Wall Common Vent Diameter — D (in.) 



Vent 
Height 

H 

(ft) 



10 



FAN FAN NAT 
+FAN±NAT+Nii'il+EAN 



92 81 K5 



1 



101 90 Ba ^ 



Combined Appliance Input Rating in Thousands of Btu per Hour 



FAN FAN 
+NAT 



NAT 



^jNA^ +FAN+NAT +Ntei-FAN+NAT +^|+FAN+NAT +pAT4-FAN+NAT+ 



140 116 



103 



FAN FAN :<. 



204 161 



FAN FAN 



FAN FAN 



309 248 



404 314 



260 



FAN FAN 



FAN FAN IvJAT, 
•im bFAN+NAT+;jjAT 



547 434 



672 520 



410 

1.65 



155 129 



HI 



224 178 



339 2 75 



444 3 48 m 



602 480 



7 40 577 



10 



110 97 !§ 



1 



169 141 



124 



243 194 



367 299 



477 377 



¥ 



649 522 



800 627 



495 



15 



125 112 J-9T 



195 164 



144" 



283 228 



427 352 



556 444 B'65 



753 612 



924 733 



565 
S40. 
740 

1451 1188 860 
975 



20 



136 123 t02l 



215 183 



160 



314 255 



475 394 



621 499 



842 688 



1035 826 



30 



152 138 HIS 



244 210 



185- 



361 297 



547 459 



720 585 



979 808 



1209 975 



50 



167 153 k34 



279 244 2:14 



421 353 



641 547 



854 706 



1164 977 F05 



100 



175 163 NA 



311 277 IsfA 



489 421 



INFAJ 



751 658 



1025 873 b5 



1408 1215 [800 



1784 1502 



136 



CHIMNEYS AND VENTS 



Table 8-10 continued 



Table 8-10 [NFPA 54:Table 13.2(a)] Continued 





Connector 
t Rise 
R 

m 














Number of Appliances: 


Two or More 






Appliance Typ 


e: 






Category I 




Appliance Vent Connection: 




Type 


B Double-Wall Vent Connector 








Type B Double-Wall Vent Connector Diameter 


-D(in.) 








12 


14 


16 


18 


20 


22 


24 


Venl 

Heigh 

H 


FAN 


nSi 

Max 

1 .«, 


f FAN 
Mm Max 


A^ppliance Input Rating Limits in Thousands of Btu per 

HM FAN NAT FAN NKj FAN NAT Vj 
VTaS Mm Max Max Min Max Max Mm Max Max Min 


Hour 
\N NAT FAN \'AT^ 


(ft) 


Min Max 


Max iMax MinMax Max 


6 


2 

4 
6 


174 764 [496 
180 897 {6i;6 
NA NA NX 


223 
230 

NA 


1046 
1231 
NA 


'65$ 
827, 
NA 


281 1371 [853. 
287 1617 108'! 
NA NA NA 


346 1772 
352 2069 
NA NA 


108( 

'iM 

;NA 


NA 
NA 
NA 


NA 
NA 
NA 


|NA 
'NA 
NA 


NA 
NA 
NA 


NA JNA NA NA \" \ 
NA iNA NA NA NAJ 
NA 'NA NA NA NA-^ 




2 
4 
6 


186 822 
192 952 
198 1050 


,516. 
644 
7?2- 


238 
244 
252 


1126 
1307 
1445 


696 

88^ 
1072 


298 1478,910, 
305 1719 1151: 
313 1902!139C 


365 1920 
372 2211 
380 2434 


use) 


NA 
471 
478 


NA 
2737 
3018 


NA 

,180^ 
218C 


NA 
560 
568 


NA ,NA NA NA NA 
3319 2180 662 3957 259^0 
3665 '264q 669 4373 3130 


10 


2 
4 
6 


196 870 
201 997 
207 1095 


536. 
6^^| 
792? 


249 
256 
263 


1195 
1371 
1509 


'-^30| 

924 

4?> 


311 1570-955 
318 1804;12U£ 
325 1989 1455 


379 2049 
387 2332 
395 2556 


m 


NA 
486 
494 


NA 
2887 
3169 


NA 
189i 
229C 


NA 
581 
589 


NA jNA NA NA N^-; 
3502 j22^0 686 4175 2710 
3849 276.0 694 4593 327'0. 


15 


2 
4 
6 


214 967 
221 1085 
228 1181 


pbH 
712 
856 


272 
279 
286 


1334 
1499 
1632 - 


1006 
1222 


336 1760 1030 
344 1978il320 
351 21571610 


408 2317 
416 2579 
424 2796 


J30i| 
i66£ 
2025 


NA 
523 
533 


NA 
3197 
3470 


|NA 
206C 

g5ic 


NA 
624 
634 


NA (NA NA NA NA^ 
3881 2490 734 4631 2960 
4216 3030 743 5035 3600_, 


20 


2 
4 
6 


223 1051 i596' 
230 1162 i748; 
237 1253 |90ffi 


291 
298 
307 


1443 84pi 
1597 l06l 
1726 , 'list, 


357 19111095 
365 2116 139~^ 
373 2287 J69^ 


430 2533 
438 2778 
450 2984 


1385 
1765 


NA 
554 
567 


NA 
3447 
3708 


iNA 
218C 
265C 


NA 
661 
671 


NA |NA NA NA NA 
4190 2630 772 5005 3130 
4511 i31?q 785 5392 3790 


30 


2 
4 
6 


216 1217 i632j 
223 1316 |7% 
231 1400 .952' 


286 
294 
303 


1664 ,910J 
1802 if^O 
1920 f4iq 


367 21831190 
376 2366 a5fq 
384 2524il83(i 


461 2891 
474 3110 
485 3299 


.15^1] 
^920 

2?!q 


NA 
619 
632 


NA 
3840 
4080 


iNA 
12365 
287£ 


NA 
728 
741 


NA |NA- NA NA NA 
4861 286t) 847 5606 3410 
4976 !348q 860 5961 4150 


bO 


2 
4 
6 


206 1479 
213 1561 
221 1631 


689' 
L03i 


273 
281 
290 


2023 loo:;? 

2139 129| 
2242 '1575^ 


350 26591315 
359 2814 1168^ 
369 2951 205q 


435 3548 
447 3730 
461 3893 


166^ 
213£ 
260£ 


NA 
580 
594 


NA 
4601 
4808 


.NA 
2632 
320£ 


NA 
709 
724 


NA NA|NA NA NA 
5569 kss 851 6633 3790 
5826 388^ 867 6943 4620 


100 


2 
4 
6 


192 1923 
200 1984 
208 2035 : 


06^ 


254 
263 
272 


2644 ;1050 
2731 134^ 
2811 164^ 


326 3490 137U 
336 3606ll760 
346 3714 215q 


402 4707 
414 4842 
426 4968 


1740 
222C 
270q 


NA 
523 
539 


NA 
5982 
6143 


[NA 
275C 
335q 


NA 
639 
654 


NA |NA,l NA NA NA. 
7254 3330 769 8650 3950 
7453 4070 786 8892 4810, 



Common Vent Capacity 













Type B Double-Wall Common Vent Diameter — D (in.) 








12 1 14 


1 


16 


18 


1 


20 


22 1 24 


Vent 

Height 

H 

(ft.) 


-.I 
FAN FAN NAT 

^FAN +NAT+NAT 


Coml 

FAN FAN piAi 
fFAN +NAT -tiNAl 


jined Applianc 

FAN FAN NAT; 
+FAN +NATiNAT 


e Input Rating 

FAN FAN NAT 
+FAN +NAT +NA'f 


in Thousand 

FAN FAN 
+FAN +NAT 


sof 

NAr 

•nat; 


Btu per Hour 

FAN FAN: NAT. 
+FAN+NATi+NA'r 


FAN FAN NA'll 
+FAN +NAT+NAtJ 


6 


900 696 '588'1 


1284 990 


1815'. 


17.^5 


1,336 kh65 


2253 1732 


k^^4 


2838 


2180 


i6fid 


3488 2677 i 1,970. 


4206 3226 .23901 


8 


994- 773 


65i 


1423 1103 


l9lf 


1927 


1491 1190- 


2507 1936 


k510 


3162 


2439 


I860!. 


3890 2998 i2200. 


4695 3616 268o1 


■ 10 ■ 


1076 841 


712'-: 


1542 1200 


1995] 


2093 


1625 ll'sOO;. 


2727 2113 


(1645' 


3444 


2665 


2030- 


4241 3278 


,zm) 


5123 3957 292&1 


15 


1247 986 


825:1 


1794 1410 


11158 


2440 


1910 a5i'd' 


3184 2484 


bio 


4026 


3133 


2360" 


4971 3862 


2790 


6016 4670 3403 


20 


1405 1116 


916 


2006 1588 


i29Q 


2722 


2147 k690'^ 


3561 2798 


.^140 


4548 


3552 


2640 


5573 4352 [3120: 


6749 5261 "38OOJ 


30 


1658 1327,1025' 


2373 1892 


;i525 


3220 


2558 ,'l99d', 


4197 3326 


252(3 


5303 


4193 


SliOi 


6539 5157 13680.' 


7940 6247 y8(5| 


50 


2024 164011280 


2911 2347 


il863 


3964. 


3183 ^430, 


5184 4149 


^075. 


6567 


5240 


380,0; 


8116 6458 14500? 


9837 7813 54^5^ 


■100 


2569 2131|1§5;0 


3732 3076 


i24Stf 


5125 


4202 13200. 


6749 5509 


[4050.- 


8597 


6986 


.50001 


106818648 |592(j- 


13004 10499 ;720g] 



137 



Table 8-11 



2007 CALIFORNIA MECHANICAL CODE 



Table 8-11 Type B Double-Wall Vent with Two or More Appliances and Single-Wall Metal Connector [NFPA 54:Table 13.2(b)] | 



Number of Appliances: 


Two or More 


Appliance Type: 


Category I 


Appliance Vent Connection; 


Single- Wall Metal Connector 



Vent Connector Capacity 





nnectoi 


Single-Wall Metal Vent Connector Diameter — D (in.) 






3 






4 


5 


6 


7 


8 


9 


10 


Venl Cc 












Appliance Input Rating 


Limits in Thousands of Btu per Hour 






Height 


Rise 






































H 


R 


FAN 


SfATI 


FAN NAT 


FAN 


VAT 


FAN 1 


VAl 


FAN 


NAT 


FAN 


NA'^ 


FAN 


NAT 


FAN 


NAT 


(ft) 


(ft) 


Min 


Max 


SSax 


Min 


Max Max 


Min 


Max 


Ts/1<b{ 


Min Max 


Max 


Min 


Max 


Max 


Min 


Max 


«Ma> 


Min 


Max 


Max 


Min Max 


.Max 


6 


1 


NA 


NA 


-26. 


NA 


NA ,,46 


NA 


NA 


;71, 


NA 


NA 


102 


207 


223 


140 


262 


293 


.183 


325 


373 


•234 


447 


463 


286 




2 


NA 


NA 


NA 


NA SS 


NA 


NA 


.-85 


168 


182 


123 


215 


251 


167 


271 


331 


■219 


334 


422 


.'281 


458 


524 


344 




3 


NA 


NA 




NA 


NA !62 


121 


131 


-s'95 


175 


198 


138 


222 


273 


188 


279 


361 


■-247 


344 


462 


;:31e 


468 


574 


385 


8 


1 


NA 


NA 


NA 


NA p8 


NA 


NA 


■.;75 


NA 


NA 


106 


226 


240 


145 


285 


316 


1:191 


352 


403 


i244 


481 


502 


-299 




2 


NA 


NA 




NA 


NA ^7 


125 


126 


r.:89' 


184 


193 


sl27 


234 


266 


173 


293 


353 


..228 


360 


450 


492 


560 


,355 
.400 




3 


NA 


NA 


. 


NA 


NA f64 


130 


138 


.I'OO 


191 


208 


a44 


241 


287 


197- 


302 


381 


.-256' 


370 


489 


501 


609 


10 


1 


NA 


NA 


NA 


NA |50 


119 


121 


s-«77 


182 


186 


JIO 


240 


253 


150 


302 


335 


1X^6 


372 


429 


*7Si 


506 


534 


■,308! 




2 


NA 


NA 




84 


85 p9- 


124 


134 


*''9i- 


189 


203 


132 


248 


278 


183 


311 


369 


i?235 


381 


473 




517 


589 


l368! 




3 


NA 


NA 




89 


91 %% 


129 


144 


J102 


197 


217 


«8 


257 


299 


203 


320 


398 


;265 


391 


511 


528 


637 


;4i3i 


15 


1 


NA 


NA 


79 


87 i$l 


116 


138 


ft81 


177 


214 


U6 


238 


291 


158 ; 


312 


380 


,'-208 


397 


482 


4266 

<Sl7 


556 


596 


"324| 




2 


NA 


NA 


■ 


83 


94 UZ 


121 


150 


¥7 


185 


230 


E138 


246 


314 


189 ' 


321 


411 


■;248 


407 


522 


568 


646 


387 




3 


NA 


NA 


'39 


87 


100 ';7i) 


127 


160 


t09 


193 


243 


157 


255 


333 


215 


331 


438 


',■281 


418 


557 


•360 


579 


690 


437 


20 


1 


49 


56 


ps'o 


78 


97 :54 


115 


152 


:?84 


175 


238 


120 


233 


325 


165 


306 


425 


,'217 


390 


538 


■X7i 


546 


664 


'.336| 




2 


52 


59 


'm 


82 


103 564 


120 


163 


,'401 


182 


252 


144 


243 


346 


197 


317 


453 


f259 


400 


574 


■831, 


558 


709 


4031 




3 


55 


62 


:m 


87 


107 Wl 


125 


172 


.113 


190 


264 


164 


252 


363 


223 


326 


476 


'294 


412 


607 


375 


570 


750 


.4571 


30 


1 


47 


60 


■31 


77 


110 •67 


112 


175 


/89 


169 


278 


129 


226 


380 


175 


296 


497 


^■230 


378 


630 


s 


528 


779 


358 




2 


51 


62 


fa7 


81 


115 if 


117 


185 


!06 


177 


290 


152 


236 


397 


208 


307 


521 


:;274 


389 


662 


541 


819 


4251 




3 


54 


64 


42 


85 


119 ^76 


122 


193 


-■120 


185 


300 


172 


244 


412 


235 


316 


542 


'309 


400 


690 


555 


855 


••4821 


50 


1 


46 


69 


;3i 


75 


128 |I6 


109 


207 


|l3 


162 


336 


i37 


217 


460 


188 


284 


604 


e245 


364 


768 


:3y 


507 


951 


^3841 




2 


49 


71 


f4o 


79 


132 wi 


114 


215 


170 


345 


164 


226 


473 


223 


294 


■623 


"293 


376 


793 


^375 


520 


983 


■458 




3 


52 


72 


•45 


83 


136 %2 


119 


221 


i'123 


178 


353 


186 


235 


486 


252 


304 


640 


f331 


387 


816 


"423 


535 


1013 


.518 


100 


1 


45 


79 


:34 


71 


150 |6l' 


104 


249 


%8 


153 


424 


i4o 


205 


585 


i92 


269 


774 


^249 


345 


993 


S321 


476 


1236 


:.393 




2 


48 


80 


=41 


75 


153 'm 


110 


255 


ai5 


160 


428 


167 


212 


593 


228 


279 


788 


>299 


358 


1011 


'^83 


490 


1259 


-469 




3 


51 


81 


!46 


79 


157 *85 


114 


260 


.129 


168 


433 


teo 


222 


603 


256 


289 


801 


339 


368 


1027 


'431 


506 1280r'527i 



Common Vent Capacity 



Type B Double-Wall Vent Diameter — D (in.) 



JLfl. 



Vent 
Height 
H 
(ft) 



FAN FAN 
4.PAN4.\'AT. 



fATi 



FAN 
*FAN 



FAN NAT 

*NAT JNTAT 



Combined Appliance Input Rating in Thousands of Btu per Hour 

r 

FAN FAN iNAt 
-fFAN -fNAT +NA% 



FAN FAN iNAT 
4.FAM*NATiNrAT 



FAN FAN 
-i-PAN .4.NAT 



:^AT 



■NfAl ■4.FAN 



FAN 



FAN 
djaAL 



A AT 



FAN 



fan isiat 
*nat4.nat: 



NA 



_i_L 



J^LA 113l. 



iaa. 



MA~ 



im 13Z iiiQ. 



J2m 158 U4. 



iU. 126- 



-218 — 123- 



334 244- 



126- 



31 n 



2SZ 



-541 429- 



33Z 



159- 



-331 269 — |ai«^ 



-436- 



-342- 



38S 



592 



-473- 



■r-Tr 



398 



-515- 



-730 56SL- 



40Z_ 



460^ 



-Jfl- 



-15- 



20 



-2[L 



JiL 



JsIA- 






JZL 



i«q iw 



-IE 



7.37 189 



1Z4_ 



-3SZ 222 234 



131 



14,5 13? 



W01 



208 



k-4 

177 tee 



_2Z5 221- 



•^nn 



-41£__343_ 



467 



369 



aoa 



-628 512- 



2S1 .617 487 



i^ /U 



^131 



J35£ 



73« 



TOO 



asfi. 



OflR 



718 '55^ 



305 247 



323 



463 383 



36 



487 



t395 



824 673 



736 7(17 



m 



512. 



1013 808 



,350 786 



25Z. 



J33 ML. 



13 



.570 



Msa 



1 59 145 



268 233 [208 



406 .3.37 



226. 



.622 S22_ 



.,.^3 



_fiad_ 



fi3E 



9.ISS 790 



saa. 



11 S3 q.is? 



11.39 9.54 



68a 



1418 11.57 



626 



223l- 



838 



_im. 



■^f'f' T^^ 



.222 2£3- 



ufa ofiK 



LIA. 



72fi_ 



_S22_ 



«46 



£1^ 



_13ZS__Llfi5_ 



_y5SL 



sm. 



138 



CHIMNEYS AND VENTS 



Table 8-12 



Table 8-12 Masonry Chimney with Two or More Appliances and Type B Double- Wall Connector [NFPA 54:Table 13.2(c)] | 



Number of Appliances: 



Appliance Type: 



Appliance Vent Connection: 



Two or More 



Category I 



Type B Double-Wall Cormector 



Vent Connector Capacity 



Vent Connecto : 



Height Rise 

H R 
(ft.) (ft.) 



FAN 



NAT 
WinMax Max 



Type B Double-Wall Vent Connector Diameter — D (in.) 



8 



10 



FAN NAT 
Min Max Max 



Appliance Input Rating Limits in Thousands of Btu per Hour 

FAN Sat 



FAN NATJ 



Min Max Maxj 



FAN 



Min Max ^x$ 



Ma% 



FAN f^'M 
Min Max Max 



Min Max Max 



FAN 



Min Max 



NAT 



FAN NATJ 
1 &? 



24 33 

26 43 

27 49 



f'SBJ 
28,' 
3^1 



39 62 

41 79 

42 92 



24 39 

26 47 

27 52 



22i; 
'2?'^ 



39 72 

40 87 
42 97 



52 106 

53 133 
55 155 



1 67.1 
•85',! 
.97 j 



65. 

67 

69 



194 l6|,i. 
230 pf 
262 143, 




104 370 
107 436 
109 491 



55 117 
57 140 
59 159 



69, 



71 
73 
75 



213 105. 
246 12g 

269 km 



94 304 
97 350 
99 383 



113 414 
116 473 
119 517 



201j 
232I 
27d; 



124 
127 
129 



479 
562 
633 



253, 

M 



145 599 -3191 
148 694 !37|l 
151 795 '43?;, 



210. 
2^, 
;276' 



134 
137 
139 



539 
615 
672 



H 

l358| 



160 776 •394 
163 848 '452'.? 



10 



24 42 

26 50 

27 55 



22' 

35-1 



38 80 

40 93 

41 105 



-12 
-4 



55 130 

57 153 

58 170 



7^ 

tioo^i 



232 lO^J 
261 a2| 

284 p.j^ 



101 324 
103 366 
106 397 



120 444 
123 498 
126 540 



.216j< 
247s 
28'!! 



142 
145 
147 



582 
652 
705 



Wm 



165 739 -34|| 
168 825 46i" 
171 893 ^4;63S; 



15 



24 48 

25 55 

26 59 



238 
35,1 



38 93 

39 105 
41 115 



54 154 

56 174 

57 189 



7A> 
89- 
1102'' 



277 JIM 
299 |1^ 
319 I5S 




125 511 
128 558 
131 597 



229 

260^ 

292^ 



153 
156 
159 



658 
718 
760 



'297' 
382 



184 824 ;37S 
187 900 '4325 
190 960 '486'! 



20 



24 52 

25 58 

26 63 






m 



37 102 

39 114 

40 123 



53 172 
55 190 
57 204 



J7: 

'1041.! 




98 437 
101 467 
104 493 



123 584 
126 625 
129 661 



[239 

[270^ 
13pi| 



150 752 
153 805 
156 851 



13125 

ml 

396. 



180 943 .39:|i 
184 1011, 45y 
187 1067 'Sbsl 



30 



24 54 

25 60 

26 64 



1255 



t36.; 



37 111 

38 122 
40 131 



-iS 
66 



52 192 
54 208 
56 221 



'95:| 



107J, 



357 ps:^ 

376 145; 

392 lim 



% 504 
99 531 
101 554 



119 680 
122 715 
125 746 



P5§ 

[2855 
f317" 



145 883 
149 928 
152 968 




m 

37fi' 

ml 



175 1115.432^ 
179 1171 4841 
182 1220,535? 



o 




65 
67 
69 



428 155.^ 
444 IJ^ 
458 |193j 



88 640 
92 660 
94 679 



115 798 
118 827 
121 854 



l2?4', 
326, 
357^ 



237^ 
260^: 

285| 



109 907 
113 933 
116 956 



140 1049 
143 1085 
147 1118 



13,92* 

m-. 



168 1334. 5pg 
172- 1379 55? 
176 1421 611? 



334 
368| 
3991 



134 1222 
138 1253 
141 1282 



.4541 



h4 



161 1589.5968 
165 1626 1 65a 
169 1661 '7051 



Common Vent Capacity 





Minimum Internal Area of Masonry Chimney Flue (in.^) 




12 1 19 1 


28 1 , 38 1 50 1 63 | 


78 1 


113 


Vent 
Height 

H 

(ft.) 


FAN FAN NAT 
+FAN+NAT ■ki'^r 


Co 

FANFANNA,T 
+FAN+NAT..NA1 


mbined Ajjpl 

FAN FAN k&l 
+FAN+NAT+^AT 


ance Inpi 

FAN FAN 
+FAN +NAT 


[tRi 

MAT 
hNAT 


ting in Thous 

FAN FAN NAT 
+FAN +NAT +NAT 


ands of Btu ] 

FAN FAN NAT 
+FAN +NAT^NA1 


jer Hour 

FAN FAN ^T 
'+FAN +NAT|NAT 


FAN 
fFAN 


FAN N\l 

fFAN \ - 1 


6 


NA 74 25 ' 


NA 119 46' 


NA 


178 fei-'; 


NA 257 


403.' 


NA 351 


143; 


NA 458 Il88^ 


NA 


582 246-'.; 


1041 


853 \A 


8 


NA 80 ar 


NA 130 §3 ' 


NA 


193 tsi' 


NA 279 


hir 


NA 384 


fift^l 


NA 501 bs" 


724 


636 278 5 


1144 


937 k"! 


10 


NA 84 Sir 


NA 138 56. 


NA 


207 ^0-' 


NA 299 


43te 


NA 409 


177'i 


606 538 (236,' 


776 


686 Ife'. 


1226 


lOlC 154 


15 


NA NA ir- 


NA 152 fe' 


NA 


233 Elbe'' 


NA 334 


152! 


523 467 


2x2! 


682 611 


2'83' 


874 


781 '3*65- 


1374 


1156 ^^6 


20 


NA NA &' 


NA NA 75' 


NA 


250 fl22' 


NA 368 


m' 


565 508 


243) 


742 668 


H25 


955 


858 '419'' 


1,513 


1286 '.'S 


30 


NA NA NA 


NA NA NA 


NA 


270 1137. 


NA 404 


'198 


615 564 


278.1 


816 747 


Im 


1067, 


969 4^'6' 


1707, 


147,- ")'■ 


50 


NANA NA 


NA NA NA"' 


NA 


NA IsTA. 


NA NA 


ISlAf 


NA 620 biS" 


879 831 


461 


1165 


1089 Ihf 


1905 


1692 "2"' 


100 


NANA WA 


NA NA NA- 


NA 


NA lijAI 


NA NA 


NA-^ 


NA NA feiSi 


NA NA 


'499. 


NA 


NA 169'; 


2053 


1921 lil-^i 



139 



Table 8-13 



2007 CALIFORNIA MECHANICAL CODE 



Table 8-13 Masonry Chimney with Two or More Appliances and Single-Wall Metal Connector [NFPA 54: Table 13.2(d)] | 



Number of Appliances: 



Appliance Type: 



Appliance Vent Connection: 



Two or More 



Category I 



Single-Wall Metal Connector 



Vent Connector Capacity 



Vent Connector 
Height Rise 
H R 

tft.) (ft.) 



Single-Wall Metal Vent Connector Diameter — D (in.) 



I 



I 



I 



JUL. 



FAN 



FAN 



c 



Min Max 



FAN 



Appliance Input Rating limits in Thousands of Btu per Hour 

FAN NAT 



Min Max MMax 



FAN 



■AT 



Min Maxl 




Min Max ^Max 



|m< 



mil 

Min Max S#x 



FAN 



FAN NATi 



Min Max 



I'Max 




NA NAfe9 
NA NAfe 
NA NARl' 



NA NA 
NA NA 
134 153 



|84| 

ml 



179 191 
186 227 
193 258 




362 474 
373 557 
381 634 



499 594 
509 696 
519 793 



316 
,376 
i437 



NA NABO 
NA NAfe 
NA NAfe 



NA NA 
137 139 
143 156 



195 208 
202 240 
210 264 



313 
323 
332 



407 g07 
465 p38 
509 1274 



387 530 
397 607 
407 663 



529 672 
540 766 
551 838 



331 
■■391 
=450 



10 



NA NA 
NA NA 

NANA ! 



NA NA|41, 
NA NAp|i 
97 102 R2 



130 151 
136 150 
143 166' 



f70 





333 
343 
352 



434 E13 
489 |k44 
530 Iot 



410 571 
420 640 
430 694 



558 727 
569 813 
580 880 



'.343 
.'403 
^59 



15 



NA NA I 
NA NA 
NA NA I 



NA NApB 
92 103 ig4 
96 112 fe 



129 151 
135 170 
141 185 



,73 



101 



199 271 
207 295 
215 315 




349 
359 
368 



502 f225 

548 Use 

586 |Z89 



445 646 
456 706 
466 755 



623 808 
634 884 
646 945 



366 
,424 

m 



20 



NA NA 

NA NA 
NA NA 



128 167 
134 185 
140 199 



J6 
90 
i03 



197 303 
205 325 
213 343 




345 
355 
365 



569 |235 
610 |266 
644 1298 



439 734 
450 787 
461 831 



614 921 
627 986 
639 1042 



387 

;4« 

i496 

:421 

473 

f524 

-^492 1 

'54S' 

597, 



30 



NA NA 
NA NA 
NA NA 



86 108 m 
91 119 & 
95 127 fe 



126 187 
132 203 
138 216 



ISO 



193 347 
201 366 
209 381 



338 
348 
358 



665 t250 
699 1282 
729 m2 



430 864 
442 908 
452 946 



600 1089 
613 1145 
626 1193 



50 



NA NA 
NA NA I 
NA NA I 



85 113 m 

89 123 pep 
94 131 



124 204 
130 218 
136 231 



:87 
ftoo 

|l2 



188 392 
196 408 
205 422 




328 
339 
349 



778 |287 
806 P20 
831 I35I 



417 1022 
429 1058 
440 1090 



582 1302 
596 1346 
610 1386 



100 




84 104 f.-49 
88 115 f 59 
93 124 ^ 67 



122 200 

127 215 1 102 

133 228 }U5 



182 410 |51 
190 425 1,69 
199 438 a88 



243 617 [232 
253 636 [254 
262 654 1279 



315 
326 
337 



875 1328 
899 [361 
921 1392 




560 1537 
575 1570 
589 1604 



580 
634 
687 



Common Vent Capacity 



Minimum Internal Area of Masonry Chimney Flue (in.^) 



Vent 
Height 

H 

(ft) 



12 



19 



28 



38 



50 



63 



78 



113 



Combined Appliance Input Rating in Thousands of Btu per Hour 




FAN FAN 
+FAN+NAT A 



FAN FAN m-T 



+FAN +NAT RTAT +FAN h-NAtImAT +FAN h-NAT SJAT 



FAN FAN 



Wr 



FAN FAN MAT 



Et 



FAN FAN fwT 
+FAN+FAN+t^AT 



NA 17® 



NA 255 B02 



NA 348 



NA 380 p2 



NA 455 g87 



NA 579 



NA 846 pvJA 



NA 191 



NA 276 PriS 



NA 497 fei7 



NA 633 



1136 928 405 



10 



NA 205 



NA 295 



NA 405 H:-75 



335 UsO 



NA 532 ^34 



771 esofioo 



12161000 450 



15 



NA 



362 j: 



NA 400 |i0 



677 602 fjgO 



866 772 



13591139 B40 



20 



NA NA 



NA 2' 



NA 



.70 



NA 503 |40 



765 661 fe21 



947 849 



14951264 640 



30 



NA NA 



NA nM.35 



NA 398 ri95 



NA 558 ^75 



808 739 f377 



1052 957^490 



1682 1447 ^40 



50 



NA NA 



NA NANA 



NA NA ,NA 



NA 612 325 



NA 821 "456 



1152 10761600 



18791672 910 



100 



NA NA 



NA NiNA 



NA NA WA 



NA NA |JA 



NA NA f494 



NA NA 663 



20061885 1046 



140 



CHIMNEYS AND VENTS 



Table 8-14 



Table 8-14 Single-Wall Metal Pipe or type B Asbestos Cement Vent with Two or More Appliances [NFPA 54: Table 13.2(e)] | 



Number of Appliances: 


Two or More 


Appliance Type: 


Draft Hood Equipped 


Appliance Vent Connection: 


Direct to Pipe or Vent 



Vent Connector Capacity 



Total vent Heigh 
(ft.) 



Connector 
Rise 
(ft.) 



Vent Connector Diameter - D (in.) 



8 



Maximum Appliance Input Rating in Thousands of Btu per Hour 



6-8 



Common Vent capacity 



21 
28 



40 
53 



68 



102 
124 



Common Vent Diameter - D (in.) 



146 
178 



205 
235 





■^ 


-3A 


M 


qs 


^A7 


9nd 


97c; 




1 


23 


44 


77 


117 


179 


240 


15 


2 


30 


56 


92 


134 


194 


265 




.^ 


P,'^ 


64 


in? 


155 


71fi 


798 




1 


25 


49 


84 


129 


190 


270 


30 


2 


31 


58 


97 


145 


211 


295 


and up 


3 


36 


68 


107 


164 


232 


321 : 







Total Vent 


Height 


4 


5 


6 


7 


8 


10 


12 


6 




48 


78 


111 


155 


205 


320 


NA 


8 




55 


89 


128 


175 


234 


365 


505 


10 




59 


95 


136 


190 


250 


395 


560 


15 




71 


115 


168 


228 


305 


■ 480 


690 


20 




80 


129 


186 


260 


340 


550 


790 


30 : 




NA 


147 


• ■ 215 


300 


400 


650 


940 


50 




NA 


NA 


, NA 


360 


490 


810 


1190 



141 



Table 8-15 



2007 CALIFORNIA MECHANICAL CODE 



Table 8-15 Exterior Masonry Chimney [NFPA 54: Table 13.2(f)] 



Special Use: Minimum Allowable Input Rating of Space-Heating Appliance in Thousands of Btu per Hour 



Number of Appliances: 


Single 


Appliance Type: 


NAT 


Appliance Vent Coimection: 


Type B Double-Wall Connector 



Vent Height 
(ft) 



-11°F or Lower 



12 



19 



Internal Area of Chimney (Square Inches) 
28 38 50 63 



78 



Local 99% Winter Design Temperature: -11°F or Lower 
Not recommended for any vent configuration 



113 



37°F or greater 






Local 99% winter 


design temperature 


37°F or greater 




6 


























8 


























10 


























15 


NA 























20 


NA 


NA 


123 


190 


249 


184 








30 


NA 


NA 


NA 


NA 


NA 


393 


334 





50 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


579 


i/Ttose-F 






Local 99% Winter 


Design Temperature: 27 to 36°F 






6 








68 


116 


156 


180 


212 


266 


8 








82 


127 


167 


187 


214 


263 


10 





51 


97 


141 


183 


201 


225 


265 


15 


NA 


NA 


NA 


NA 


233 


253 


274 


305 


20 


NA 


NA 


NA 


NA 


NA 


307 


330 


362 


30 


NA 


NA 


NA 


NA 


NA 


419 


445 


485 


50 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


763 


17°Fto26°F 






Local 99% Winter 


Design Temperature: 17 to 26°F 






6 


NA 


NA 


NA 


NA 


NA 


215 


259 


349 


8 


NA 


NA 


NA 


NA 


197 


226 


264 


352 


10 


NA 


NA 


NA 


NA 


214 


245 


278 


358 


15 


NA 


NA 


NA 


NA 


NA 


296 


331 


398 


20 


NA 


NA 


NA 


NA 


NA 


352 


387 


457 


30 


NA 


NA 


NA 


NA 


NA 


NA 


507 


581 


50 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


5-Ftol6T 






Local 99% Winter 


Design Temperature: 5 to 16°F 






6 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


416 


8 


NA 


NA 


NA 


NA 


NA 


NA 


312 


423 


10 


NA 


NA 


NA 


NA 


NA 


289 


331 


430 


15 


NA 


NA 


NA 


NA 


NA 


NA 


393 


485 


20 


NA 


NA 


NA 


NA 


NA 


NA 


450 


547 


30 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


682 


50 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


972 


-lO'F to4"F 






Local 9970 Wmter 


Design Temperature: -iu wi f 






6 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


484 


8 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


494 


10 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


513 


15 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


586 


20 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


650 


30 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


805 


50 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


1003 



142 



CHIMNEYS AND VENTS 



Table 8-1 6 -Table 8-1 7 



Table 8-16 Exterior Masonry Chimney [NFPA 54: Table 13.2(f)] 



Special Use: 


Combined Appliance Maximum Input Rating in 


Thousands o 


f Btu per 


Hour 


Number of Applications: 




Two 


Dr More 








Appli 


ance Type: 






NAT 


+ NAT 








Appliance Vent Connection: 




Type 


B Double-Wall Connector 




Vent 




Internal Area 


of Chimneys (Square Inches) 








Height 
(ftl 




12 19 


28 


38 




50 


63 


78 


113 


6 




25 46 


71 


103 




143 


188 


246 


NA 


8 




28 , 53 


82 


119' 




163 


218 


278 


408 


10 




31 56 


90 


131- 




177 


236 


302 


454 ■ 


15 




NA 67 


106 


152 




212 


283 


365 


546 


20 




NA NA 


NA 


NA 




NA 


325 


419 


648 


30 




NA NA 


NA 


NA 




NA 


NA 


496 


749 


50 
100 




NA NA • 
NA - NA 


NA 
NA 


NA 
NA 




NA 
NA 


NA 
NA 


NA 
NA 


922 
NA 



Table 8-17 Exterior Masonry Chimney [NFPA 54: Table 13.2(g)] 



Special Use: 






Combined Appliance Minimum Input Ratine in 


Thousands of Btu per 


Hour 


Number of 


Applications: 


Two 


ai More 








Appliance Type: 


NAT 


+ NAT 








Appliance ' 


Vent Connection: 


Type 


B Double-Wall Connector 






Vent 


Internal Area of Chimney (Square Inches) 


Height 
(ft) 


12 




19 


28 38 


50 


63 


78 


113 


37T or Greater 








Local 99% Winter Design Temperature: 
37°F or Greater 








6 










, 











NA 


8 

























10 










. 














15 


NA 




. 

















20 


NA 




NA 


NA NA 


NA 


184 








30 


NA 




NA 


NA NA 


NA 


393 


334 





50 


NA 




NA 


NA " NA 


NA 


NA 


NA 


579 


100 


NA 




NA 


NA • NA 


NA 


NA 


NA 


NA 


27Tto36T 








Local 99% Winter Design Temperature: 
















27to36T 










6 










68 NA 


NA 


180 


212 


NA 


8 










82 NA 


NA 


187 


214 


263 


10 







51 


NA NA 


NA 


201 


225 


265 


15 


NA 




NA 


NA NA 


NA 


253 


274 


305 


20 


NA 




NA 


NA NA 


NA 


307 


330 


362 


30 


NA 




NA 


NA NA 


NA 


NA 


445 


485 


50 


NA 




NA 


NA NA 


NA 


NA 


NA 


763 


100 


NA 




NA 


NA NA 


NA 


NA 


NA 


NA 



143 



Table 8-17 continued - Table 8-18 



2007 CALIFORNIA MECHANICAL CODE 



Table 8-17 [NFPA 54: Table 13.2(g)] Continued 





17T to 26°F 






Local 99% Winter Design Temperature: 
















17 to 26°F 










6 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


8 


NA 


NA 


NA 


NA 


NA 


NA 


264 


352 


10 


NA 


NA 


NA 


NA 


NA 


NA 


278 


358 


15 


NA 


NA 


NA 


NA 


NA 


NA 


331 


398 


20 


NA 


NA 


NA 


NA 


NA 


NA 


387 


457 


30 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


581 


50 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


862 


100 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


5 to 16°F 






Local 99% Winter Design Temperature: 
















5 to 16°F 










6 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


8 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


10 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


430 


15 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


485 


20 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


547 


30 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


682 


50 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


100 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


4°F or Lower 






Local 99% Winter Design Temperature: 
















4°F or Lower 
















Not recommended for any 


vent confieurati 


ons 







Table 8-18 Exterior Masonry Chimney with Two or More Appliances, FAN + NAT [NFPA 54: Table 13.2(h)] 



Special Use: 



Combined Appliance Maximum Input Rating in Thousands of Btu per Hour 



Number of Applications: 






Two 01 


More 










Appliance 


Type 








FAN + 


NAT 










Appliance 


Vent Connection: 


Type B Double-Wall Connector 


Vent 






















Height 










Internal Area of Chimney (Square 


Inches) 






(ft) 


12 




19 


28 


38 


50 




63 


78 


113 


6 


74 




119 


178 


257 


351 




458 


582 


853 


8 


80 




130 


193 


279 


384 




501 


636 


937 


10 


84 




138 


207 


299 


409 




538 


686 


1010 


15 


NA 




152 


233 


334 


467 




611 


781 


1156 


20 


NA 




NA 


250 


368 


508 




668 


858 


1286 


30 


NA 




NA 


NA 


404 


564 




747 


969 


1473 


50 


NA 




NA 


NA 


NA 


NA 




831 


1089 


1692 


100 


NA 




NA 


NA 


NA 


NA 




NA 


NA 


1921 



144 



CHIMNEYS AND VENTS 



Table 8-19 



Table 8-19 Exterior Masonry Chimney with Two or More Appliances, FAN + NAT [NFPA 54: Table 13.2{i)] 



Special Use: 



Minimum Allowable Input Rating of Space-Heating Appliance in Thousands of 
Btu per Hour 



Number of Applications: 



Appliance Type: 



Appliance Vent Connection: 



Two or More 



FAN + NAT 



Type B Double-Wall Connector 



Vent 

Height 

(ft)^ 



12 



Internal Area of Chimney (Square Inches) 
19 28 38 50 



63 



78 



113 



37°F or greater 



10 
15 
20 
30 
50 
100 



27°F to 36°F 



10 
15 
20 
30 
50 
100 



17Tto26°F 








NA 
NA 
NA 
NA 
NA 








NA 
NA 
NA 
NA 
NA 



Local 99% Winter Design Temperature: 
37°F or Greater 










NA 
NA 
NA 
NA 










123 
NA 
NA 
NA 











190 
334 
NA 
NA 










249 
398 
NA 
NA 











184 
393 
714 
NA 



Local 99% Winter Design Temperature: 
27^ to 36°F 







51 
111 
NA 
NA 
NA 
NA 



68 
82 
97 
142 
187 
NA 
NA 
NA 



116 
127 
141 
183 
230 
330 
NA 
NA 



156 
167 
183 
233 
284 
319 
NA 
NA 



180 
187 
210 
253 
307 
419 
672 
NA 



Local 99% Winter Design Temperature: 
17°F to 26°F 



Not recommended for any vent configurations 












334 
707 
NA 



212 
214 
225 
274 
330 
445 
705 
NA 














579 
1600 



266 
263 
265 
305 
362 
485 
763 
1554 



6 





55 


99 


141 


182 


215 


259 


349 


8 


52 


74 


111 


154 


197 


226 


264 


352 


10 


NA 


90 


125 


169 


214 


245 


278 


358 


15 


NA 


NA 


167 


212 


263 


296 


331 


398 


20 


NA 


NA 


212 


258 


316 


352 


387 


457 


30 


NA 


NA 


NA 


362 


429 


470 


507 


581 


50 


NA 


NA 


NA 


NA 


NA 


723 


766 


862 


100 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


1669 


5°Ftol6T ' 






Local 99% Winter Design Temperature: 
















5 to 16°F 










6 


NA 


78 


121 


166 


214 


252 


301 


416 


8 


NA 


94 


135 


182 


230 


269 


312 


423 


10 


NA 


111 


149 


198 


250 


289 


331 


430 


15 


NA 


NA 


193 


247 


305 


346 


393 


485 


20 


NA 


NA 


NA 


293 


360 


408 


450 


547 


30 


NA 


NA 


NA 


377 


450 


531 


580 


682 


50 


NA 


NA 


NA 


NA 


NA 


797 


853 


972 


100 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


1833 


-10°Fto4T 






Local 99% Winter Design Temperature: 
















-10"'Fto4"'F 










6 


NA 


NA 


145 


196 


249 


296 


349 


484 


8 


NA 


NA 


159 


213 


269 


320 


371 


494 


10 


NA 


NA 


175 


231 


292 


339 


397 


513 


15 


NA 


NA 


NA 


283 


351 


404 


457 


586 


20 


NA 


NA 


NA 


333 


408 


468 


528 


650 


30 


NA 


NA 


NA 


NA 


NA, 


603 


667 


805 


50 . 


NA 


NA 


NA 


NA 


NA 


NA 


955 


1003 


100 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


NA 


-11°F or Lower 






Local 99% Winter Design Temperature: 

—1 1 "F nr T .mA/pr 









145 



2007 CALIFORNIA MECHANICAL CODE 



146 



CHAPTER 9 

INSTALLATION OF SPECIFIC EQUIPMENT 
Note: Portions of this chapter have been reproduced in their entirety from NFPA 54-2002 (ANSI Z223.1) 






901 .0 Scope. 

Warm air heating systems, vented decorative 
appliances, floor furnaces, vented wall furnaces, unit 
heaters and room heaters shall comply with the 
general requirements of Chapter 3 of this code, in 
addition to the requirements of this chapter. 

902.0 General. 

(A) This chapter is applicable primarily to 
nonindustrial-type gas utilization equipment 
and installations and, unless specifically 
indicated, does not apply to industrial-type 
equipment and installations. Listed gas 
utilization equipment shall be installed in 
accordance with their listing and the 
manufacturers' instructions, or as elsewhere 
specified in this chapter. Unlisted equipment 
shall be installed as specified in this part as 
applicable to the equipment. For additional 
information concerning particular gas eqtdpment 
and accessories, including industrial types, 
reference can be made to the standards listed in 
Chapter 17. 

(B) Gas utilization equipment shall not be installed 
so its combustion, ventilation, and dilution air 
are obtained only from a bedroom or bathroom 
unless the bedroom or bathroom has the 
required volume in accordance with Section 701.2. 

(C) Where the room size in comparison with the size 
of the equipment is to be calculated, the total 
volume of the appliance is determined from 
exterior dimensions and is to include fan 
compartments and burner vestibules, where 
used. Where tlie actual ceiling height of a room 
is greater than eight (8) feet (2.4 m), the volume 
of the room is figured on the basis of a ceiling 
height of 8 ft. (2.4 m). [NFPA 54:9.1] 

(D) [For OSHPD 1,2&4] Warm air furnaces shall not 
he installed under openable windows on exterior walls. 

903.0 Air-Conditioning Equipment (Gas-Fired Air 
Conditioners and Heat Pumps). 

903.1 Independent Gas Piping. Gas piping serving 
heating gas utilization equipment shall be permitted 
to also serve cooling equipment where heating and 
cooling equipment cannot be operated simulta- 
neously. (See Section 1309.4.) [NFPA 54: 9.2.1] 



903.2 Connection of Gas Engine-Powered Air 
Conditioners. To protect against the effects of normal 
vibration in service, gas engines shall not be rigidly 
connected to the gas supply piping. [NFPA 54: 9.2.2] 

903.3 Clearances for Indoor Installation. The 

installation of air-conditioning equipment shall 
comply with the following requirements: 

(A) Listed air-conditioning equipment installed in 
rooms that are large in comparison with the size 
of the equipment shall be installed with 
clearances per the terms of their listing and the 
manufacturer's instructions. (See Table 9-1.) 

(B) Air-conditioning equipment installed in rooms 
that are NOT large (such as alcoves and closets) 
in comparison with the size of the equipment 
shall be listed for such installations and installed 
in accordance with the manufacturer's instruc- 
tions. Listed clearances shall not be reduced by 
the protection methods described in Table 5-3, 
regardless of whether the enclosure is of combus- 
tible or noncombustible material. 

(C) Unlisted air-conditioning equipment shall be 
installed with clearances from combustible 
material of not less than eighteen (18) inches (460 
mm) above the equipment and at the sides, 
front, and rear, and nine (9) inches (230 mm) 
from the draft hood. 

(D) Air-conditioning equipment (listed and unlisted) 
installed in rooms that are large in comparison 
with the size of the equipment shall be permitted 
to be installed with reduced clearances to 
combustible material provided the combustible 
material or equipment is protected as described 
in Table 5-3 [see 5-3(2)]. 

(E) Where the furnace plenum is adjacent to plaster 
on metal lath or noncombustible material 
attached to combustible material, the clearance 
shall be measured to the surface of the plaster or 
other noncombustible finish where the clearance 
specified is two (2) inches (50 mm) or less. 

(F) Listed air-conditioning equipment shall have the 
clearance from supply ducts within three (3) feet 
(0.9m) of the furnace plenum be not less than that 
specified from the furnace plenum. No clearance 
is necessary beyond this distance. [NFPA 54: 9.2.3] 

903.4 Assembly and Installation. Air-conditioning 
equipment shall be installed in accordance with the 
manufacturer's instructions. Urdess the eqtdpment is 



147 



903.4 - 904.2 



2007 CALIFORNIA MECHANICAL CODE 



listed for installation on a combustible siirface, such 
as a floor or roof, or unless the surface is protected in 
an approved manner, it shall be installed on a surface 
of noncombustible construction with noncombustible 
material and surface finish and with no combustible 
material against the tmderside thereof. [NFPA 54: 9.2.4] 

903.5 Furnace Plenums and Air Ducts. A furnace 
plenum supplied as a part of the air-conditioning 
equipment shall be installed in accordance with the 
manufacturer's instructions. Where a furnace 
plenum is not supplied with the equipment, any 
fabrication and installation instructions provided by 
the manufacturer shall be followed. The method of 
coimecting supply and return ducts shall facilitate 
proper circulation of air. [NFPA 54: 9.2.5] 

903.6 Refrigeration Coiis. (See Sections 904.7 and 
904.8)[NFPA 54: 9.2.6] 

903.7 Switches in Eiectricai Suppiy Line. Means 
for interrupting the electrical supply to the air- 
conditioning equipment and to its associated cooling 
tower (if supplied and installed in a location remote 
from the air conditioner) shall be provided within 
sight of and not over fifty (50) feet (15 m) from the 
air-conditioner and cooling tower. [NFPA 54: 9.2.7] 

904.0 Centrai l-leating Boilers and Furnaces. 

904.1 Location. Central heating furnace and low- 
pressure boiler installations in bedrooms or battirooms 
shall comply with one of the following: 

(1) Central heating furnaces and low-pressure boilers 
may be installed in a closet located in the bedroom 
or bathroom, provided the closet is eqtiipped with 
a listed, gasketed door assembly and a listed, self- 
closing device. The self-closing door assembly 
shall meet the requirements of section 904.1.1. The 
door assembly shall be installed with a threshold 
and bottom door seal and shall meet the 
requirements of section 904.1.2. All combustion air 
for such installations shall be obtained from the 
outdoors. The closet shall be for the exclusive use 
of the central heating furnace or low-pressure 
boiler. 

(2) Central heating furnaces and low-presstire boilers 
shall be of the direct-vent t5^e. 

904.1 .1 Seif-Closing Doors. Self-closing doors 
shall swing easily and freely and shall be 
equipped with a self-closing device to cause the 
door to dose and latch each time it is opened. The 
closing mechanism shall not have a hold-open 
feature. [NFPA 80: 2-1.4.1] 

904.1.2 Gasi<eting. Gasketing on gasket doors or 
frames shall be furnished only in accordance with 
the published listings of the door, frame, or 
gasketing material manufacturer. 



Exception: Where acceptable to the Authority 
Having Jurisdiction, gasketing of noncombustible 
or limited-combustible material (see NFPA 220, 
Standard on Tj^es of Building Construction) shall 
be permitted to be applied to the frame, provided 
dosing and latching of the door are not inhibited. 
[NFPA 80: 2-4.8] 

904.2 Clearance. 

(A) Listed central heating furnaces and low-pressure 

boilers installed in rooms that are large in 
comparison with the size of the eqtdpment shall 
be installed with clearances per the terms of 
their listings and the manufacturers' instructions. 
(See Sections 208.0 and 1004.0 for definition.) 

(B) Central-heating furnaces and low-pressure 
boilers installed in rooms that are NOT large 
(such as alcoves and closets) in comparison with 
the size of the equipment shall be listed for such 
installations. Listed clearances shall not be 
reduced by the protection methods described in 
Table 5-3 and illustrated in Figures 9-1 (a) 
through 9-l(c), regardless of whether the 
enclosure is of combustible or noncombustible 
material. 

(0) Unlisted central-heating furnaces and low- 
pressure boilers installed in rooms that are large 
in comparison with the size of the equipment 
shall be installed with clearances not less than 
those specified in Table 9-1. 

(D) Central-heating furnaces and low-pressure 
boilers (listed and unlisted) installed in rooms 
that are large in comparison with the size of the 
equipment shall be permitted to be installed 
with reduced clearances to combustible material 
provided the combustible material or equipment 
is protected as described in Table 5-3. 

(E) Front clearance shall be sufficient for servicing 
the burner and the furnace or boiler. 

(F) Where the furnace plenum is adjacent to plaster 
on metal lath or noncombustible material 
attached to combustible material, the clearance 
shall be measured to the stirf ace of the plaster or 
other noncombustible finish where the clearance 
spedfied is two (2) inches (50 nun) or less. 

(G) The clearance to this equipment shall not 
interfere with combustion air, draft hood 
clearance and relief, and accessibility for 
servicing. (See Sections 305.1, 701.1, and 802.12.7.) 

(H) Listed central heating furnaces shall have the 
dearance from supply ducts within three (3) feet 
(0.9 m) of the furnace plenum be not less than 
that specified from the furnace plenum. No 
dearance is necessary beyond this distance. 

(1) Unlisted central heating furnaces with 



148 



INSTALLATION OF SPECIFIC EQUIPMENT 



Figure 9-1 (a) -904.7 



H 



Construction using combustible • 
material, plastered or unplastered 



M 



M M 



I 



M 





Sheet metal or 
other protection 



Gas equipment 
or vent connector 



Notes: 

A equals the clearance with no protection. 

B equals the reduced clearance permitted. The protection applied to the construction using combustible material 

shall extend far enough in each direction to make C equal to A. 

FIGURE 9-1 (a) Extent of Protection Necessary to Reduce Clearance from Gas Equipment or Vent 

Connectors. 



temperature limit controls that cannot be set 
higher than 250°F (121°C) shall have the 
clearance from supply duct within six (6) feet 
(1.8 m) of the furnace plenum be not less than six 
(6) inches (150 mm). No clearance is necessary 
beyond this distance. 

(J) Central-heating furnaces other than those listed 
in 904.2 (h) or (i) shall have clearances from the 
supply ducts of not less than eighteen (18) inches 
(0.46 m) from the furnace plenum for the first 
three (3) feet (0.9 m), then six (6) inches (150 mm) 
for the next three (3) feet (0.9 m) and one (1) inch 
(25 mm) beyond six (6) feet (1.8 m). [NFPA 54: 9.3.2] 

904.3 Assembly and Installation. A central-heating 
boiler or furnace shall be installed in accordance with 
the manufacturer's instructions and shall be installed 
on a floor of noncombustible construction with 
noncombustible flooring and surface finish and with 
no combustible material against the underside 
thereof, or on fire-resistive slabs or arches having no 
combustible material against the underside thereof. 

Exception: 

(1) Appliances listed for installation on a 
combustible floor. 

(2) Installation on a floor protected in an 
approved manner. [NFPA 54:9.3.3] 

904.4 Temperature- or Pressure-Limiting Devices. 

Steam and hot water boilers, respectively, shall be 
provided with approved automatic limiting devices 
for shutting down the burner(s) to prevent boiler 
steam pressure or boiler water temperature from 



exceeding the maximum allowable working pressure 
or temperature. Safety limit controls shall not be used 
as operating controls. [NFPA 54:9.3.4] 

904.5 Low-Water Cutoff. Hot water boilers installed 
above the radiation level and all steam boilers shall 
be provided with an automatic means to shut off the 
fuel supply to the burner(s) if the boiler water level 
drops to the lowest safe water line. [NFPA 54:9.3.5] 

904.6 Steam Safety and Pressure-Relief Valves. 

Steam and hot water boilers shall be equipped, 
respectively, with listed or approved steam safety or 
pressure-relief valves of appropriate discharge 
capacity and conforming with ASME requirements. 
A shutoff valve shall not be placed between the relief 
valve and the boiler or on discharge pipes between 
such valves and the atmosphere. 

(1) Relief valves shall be piped to discharge near the 
floor. 

(2) The entire discharge piping shall be at least the 
same size as the relief valve discharge piping. 

(3) Discharge piping shall not contain a threaded 
end cormection at its termination point. [NFPA 
54:9.3.6] 

904.7 Furnace Plenums and Air Ducts. 

(A) Furnace plenums and air ducts shall be installed 
in accordance with NFPA 90A, Standard for the 
Installation of Air-Conditioning and Ventilating 
Systems, or NFPA 90B, Standard for the 
Installation of Warm- Air Heating and Air- 
Conditioning Systems. 

(B) A furnace plenum supplied as a part of a furnace 



149 



Figure 9-1 (b)- 904.9 



2007 CALIFORNIA MECHANICAL CODE 




Mounted with side 
and top edges open 



Mounted witli top 
and bottom edges 
open 



Wall protector installed in corner 



Wall protector mounted 
on single flat wall 



Must be mounted with lop 
and bottom edges open 




Nail or screw anchor 



Clearance 
reduction system 



1 in. (25 mm) nonoombustible 
spacer such as stacked washers, 
small-diameter pipe, tubing, or 
electrical conduit 



IVIasonry walls can be attached to combustible walls using wall ties. 
Spacers should not be used directly behind appliance or connector. 



FIGURE 9-1 (b) Wall Protector Clearance 
Reduction System. 



^1 

space ^>>' 



Combustible wall 



1 in. (25 mm) 
minimum air space 
between masonry 
and combustible wall 



4 in. (100 mm) 

nominal brick wall 



Bottom and top course ■ 
of briol<s staggered for 
ventilation 



A strip of heavy-gauge steel 
used for added support 

Note: Do not place masonry wall ties directly 
beliind appliance or connector. 




P_ Masonry wall tie 



FIGURE 9-1 (c) Masonry Clearance Reduction 
System. 



shall be installed in accordance with the 
manufacttirer's instructions. 

(C) Where a furnace plenum is not supplied with 
the furnace, any fabrication and installation 
instructions provided by the manufacturer shall 
be followed. The method of connecting supply 
and return ducts shall facilitate proper 
circulation of air. 

(D) Where a furnace is installed so supply ducts 
carry air circulated by the furnace to areas out- 
side the space containing the furnace, the return 
air shall also be handled by a duct(s) sealed to 
the furnace casing and terminating outside the 
space containing the furnace. [NFPA 54:9.3.7] 

904.8 Refrigeration Colls. The installation of 
refrigeration coils shall comply with the following 
requirements: 

(A) A refrigeration coil shall not be installed in 
conjunction with a forced-air furnace where 
circulation of cooled air is provided by the 
furnace blower, unless the blower has Sufficient 
capacity to overcome the external static resistance 
imposed by the duct system and cooling coil 
and the air throughput necessary for heating or 
cooling, whichever is greater. 

(B) Furnaces shall not be located upstream from 
cooling units, unless the cooling tmit is designed 
or equipped so as not to develop excessive 
temperature or pressure. 

(C) Refrigeration coils shall be installed in parallel 
with or on the downstream side of central 
furnaces to avoid condensation in the heating 
element, tmless the furnace has been specifically 
listed for downstream installation. With a 
parallel flow arrangement, the dampers or other 
means used to control flow of air shall be 
sufficiently tight to prevent any circulation of 
cooled air through the furnace. 

(D) Means shall be provided for disposal of 
condensate and to prevent dripping of 
condensate on the heating element. [NFPA 54:9.3.8] 

904.9 Cooling Units Used with Heating Boilers. 

(A) Boilers, where used in conjunction with 
refrigeration systems, shall be installed so that 
the chilled medium is piped in parallel with the 
heating boiler with appropriate valves to 
prevent the chilled medium from entering the 
heating boUer. 

(B) Where hot-water-heating boilers are cormected 
to heating coils located in air-handling units 
where they can be exposed to refrigerated air 
circulation, such boiler piping systems shall be 
equipped with flow control valves or other 
automatic means to prevent gravity circulation 
of the boiler water during the cooling cycle. 
[NFPA 54:9.3.9] 



150 



INSTALLATION OF SPECIFIC EQUIPMENT 



904.10-904.11 



904.10 Equipment on Roofs. 

904.10.1 General. 

904.10.1.1 Gas utilization equipment on 
roofs shall be designed or enclosed so as to 
withstand climatic conditions in the area in 
which it is installed. Where enclosures are 
provided, each enclosure shall permit easy 
entry and movement, shall be of reasonable 
height, and shall have at least a thirty (30) 
inch (760 mm) clearance between the entire 
service access panel(s) of the equipment and 
the wall of the enclosure. 

904.10.1.2 Roofs on which equipment is to 
be installed shall be capable of supporting 
the additional load or shall be reinforced to 
support the additional load. 

904.10.1.3 All access locks, screws, and 
bolts shall be of corrosion-resistant material. 

904.10.2 Installation of Equipment on Roofs. 

904.1 0.2.1 Gas utilization eqtiipment shall be 
installed in accordance with its listing and 
the manufacturer's installation instructions. 

904.10.2.2 Equipment shall be installed on a 
well-drained surface of the roof. At least 6 ft. 
(1.8 m) of clearance shall be available 
between any part of the equipment and the 
edge of a roof or similar hazard, or rigidly 
fixed rails, guards, parapets, or other 
building structures at least forty-two (42) 
inches (1.1 m) in height shall be provided on 
the exposed side. 

904.10.2.3 All equipment requiring an 
external source of electrical power for its 
operation shall be provided with (1) a 
readily accesible electrical disconnecting 
means within sight of the equipment that 
will completely de-energize the equipment, 
and (2) a 120 V AC groimding-type receptacle 
outlet on the roof adjacent to the equipment. 
The receptacle outlet shall be on the supply 
side of the disconnect switch. 

904.10.2.4 Where water stands on the roof 
at the equipment or in the passageways to 
the equipment, or where the roof is of a 
design having a water seal, a suitable 
platform, walkway, or both shall be provided 
above the waterline. Such platform(s) or 
walkway(s) shall be located adjacent to the 
equipment and control panels so that the 
equipment can be safely serviced where 
water stands on the roof. 

904.1 0.3 Access to Equipment on Roofs. 

904.10.3.1 Gas utilization equipment 
located on roofs or other elevated locations 
shall be accessible. 



904.10.3.2 Bvuldings of more than fifteen (15) 
feet (4.6 m) in height shall have an inside 
means of access to the roof, unless other 
means acceptable to the Authority Having 
Jurisdiction are used. 

904.10.3.3 The inside means of access shall 
be a permanent or foldaway inside stairway 
or ladder, terminating in an enclosure, 
scuttle, or trapdoor. Such scuttles or 
trapdoors shall be at least twenty-two (22) 
inches x twenty-four (24) inches (560 nam x 
610 mm) in size, shall open easily and safely 
under all conditions, especially snow, and 
shall be constructed so as to permit access 
from the roof side unless deliberately locked 
on the inside. At least six (6) feet (1.8 m) of 
clearance shall be available between the 
access opening and the edge of the roof or 
similar hazard, or rigidly fixed rails or guards 
a minimtim of forty-two (42) inches (1.1 m) in 
height shall be provided on the exposed side. 
Where parapets or other building structures 
are utilized in lieu of guards or rails, they 
shall be a minimum of forty-two (42) inches 
(1.1 m) in height. 

904.10.3.4 Permanent lighting shall be 
provided at the roof access. The switch for 
such lighting shall be located inside the 
building near the access means leading to 
the roof. 

904.1 1 Appliances in Attics. 

904.11.1 Attic Access. An attic in which an 
appliance is installed shall be accessible through 
an opening and passageway at least as large as 
the largest component of the appliance, and not 
less than twenty-two (22) inches x thirty (30) 
inches (560 mm x 760 nmi). 

904.11.2 Where the height of the passageway is 
less than six (6) feet (1.8m), the distance from the 
passageway access to the appliance shall not 
exceed twenty (20) feet (6.1m.) measured along 
the center-line of the passageway. 

904.1 1 .3 The passageway shall be unobstructed 
and shall have solid flooring not less than 
twenty-four (24) inches (610 mm) wide from the 
entrance opening to the appliance. 

904.11.4 Work Platform. A level working 
platform not less than thirty (30) inches (760 
mm) by thirty (30) inches shall be provided in 
front of the service side of the appliance. 

904.11.5 Lighting and Convenience Outlet. A 

permanent 120-volt receptacle outlet and a 
lighting fixture shall be installed near, the 



151 



904.11 -907.2 



2007 CALIFORNIA MECHANICAL CODE 



appliance. The switch controlling the lighting 
fixture shall be located at the entrance to the 
passageway. [NFPA 54: 9.5] 

905.0 Clothes Dryers. 

905.1 Clearance. The installation of clothes dryers 
shall comply with the following requirements: 

(A) Listed Type 1 clothes dryers shall be installed 
with a minimum clearance of six (6) inches (150 mmi) 
from adjacent combustible material. Clothes 
dryers listed for installation at reduced 
clearances shall be iastalled in accordance with 
their listing. Type 1 clothes dryers installed in 
closets shall be specifically listed for such 
installation. 

(B) Listed Type 2 clothes dryers shall be installed 
with clearances of not less than that shown on the 
marking plate and in the manufacturers' 
instructions. Type 2 clothes dryers designed and 
marked, "For use only in noncombustible 
locations," shall not be installed elsewhere. 

(C) Unlisted clothes dryers shall be installed with 
clearances to combustible material of not less 
than eighteen (18) inches (460 mm). Combustible 
floors under unlisted clothes dryers shall be 
protected in an approved manner. [NFPA 54:9.4.1] 

905.2 Exhausting to the Outdoors. 

(A) Type 1 and Type 2 clothes dryers shall be 
exhausted to the outside air. [NFPA 54:9.4.2] 

905.3 Provisions for Makeup Air. 

(A) Makeup air shall be provided for Type 1 clothes 
dryers in accordance with the manufacturers' 
installatiori instructions. 

(B) Provision for makeup air shall be provided for 
Type 2 clothes dryers, with a minimum free area 
(see Section 701.6) of 1 in.^ (6.5 m^) for each 1000 
Btu/h (2200 mmVkW) total input rating of the 
dryer(s) installed. [NFPA 54:9.4.3] 

905.4 Exhaust Ducts for Type 1 Clothes Dryers. 

(A) A clothes dryer exhaust duct shall not be 
connected into any vent connector, gas vent, 
chimney, crawl space, attic, or other similar 
concealed space. 

(B) Ducts for exhausting clothes dryers shall not be 
assembled with screws or other fastening means 
that extend into the duct and that would catch 
lint and reduce the efficiency of the exhaust 
system. 

(C) Exhaust ducts shall be constructed of rigid 
metallic material. Transition ducts used to 
connect the dryer to the exhaust duct shall be 



listed for that application or installed in 
accordance with the clothes dryer manufacturer's 
installation instructions. [NFPA 54:9.4.4] 

905.5 Exhaust Ducts for Type 2 Clothes Dryers. 

(A) Exhaust ducts for Type 2 clothes dryers shall 
comply with Section 905.4. 

(B) Exhaust ducts for Type 2 clothes dryers shall be 
constructed of sheet metal or other noncombustible 
material. Such ducts shall be equivalent in 
strength and corrosion resistance to ducts made 
of galvanized sheet steel not less than 0.0195 
inch (0.5 mm) thick. 

(C) Type 2 clothes dryers shall be equipped or 
installed with lint-controlling means. 

(D) Exhaust ducts for Type 2 clothes dryers shall be 
installed with a minimum clearance of six (6) 
inches (150mm) from adjacent combustible 
material. Where exhaust ducts for Type 2 clothes 
dryers are installed with reduced clearances, the 
adjacent combustible material shall be protected 
in accordance with Table 5-3. 

(E) Where ducts pass through walls, floors, or 
partitions, the space around the duct shall be 
sealed with noncombustible m.aterial. 

(F) Multiple installations of Type 2 clothes dryers 
shall be made in a maimer to prevent adverse 
operation due to back pressures that might be 
created in the exhaust systems. [NFPA 54:9.4.5] 

905.6 Multiple Family or Public Use. All clothes 
dryers installed for multiple-family or public use 
shall be equipped with approved safety shutoff 
devices and shall be installed as specified for a Type 
2 clothes dryer under Section 905.5. [NFPA 54:9.4.6] 

906.0 Conversion Burners. Installation of 
conversion burners shall conform to ANSI Z21.8, 
Standard for Installation of Domestic Gas Conversion 
Burners. [NFPA 54:9.5] 

907.0 Decorative Appliances for Installation in 
Vented Fireplaces. 

907.1 Prohibited Installations. Decorative appliances 
for installation in vented fireplaces shall not be 
installed in bathrooms or bedrooms unless the 
appliance is listed and the bedroom or bathroom has 
the required volume in accordance with Section 
701.2. [NFPA 54:9.6.1] [For OSHPD 1, 2 & 4] A 
vented decorative appliance shall not he located in any 
hospital, skilled nursing facility, intermediate care facility 
or correctional treatment center. 

907.2 Installation. A decorative appliance for 
installation in a vented fireplace shall be installed 



152 



INSTALLATION OF SPECIFIC EQUIPMENT 



907.2 - 909.4 



only in a vented fireplace having a working chimney 
flue and constructed of noncombustible materials. 
These appliances shall not be thermostatically 
controlled. 

(1) A listed decorative appliance for installation 
in a vented fireplace shall be installed in 
accordance with its listing and the 
manufacturer's instructions. 

(2) A decorative appliance for installation in a 
vented fireplace where installed in a 
manufactured home shall be listed for 
installation in manufactured homes. 

(3) An unlisted decorative appliance for 
installation in a vented fireplace shall be 
installed in a fireplace having a permanent 
free opening, based on appliance input rat- 
ing and chimney height equal to or greater 
than that specified in Table 9-2. [NPPA 54:9.6.2] 

907.3 Fireplace Screens. A fireplace screen shall be 
installed with a decorative appliance for installation 
in a vented fireplace. [NFPA 54:9.6.3] 

908.0 Gas Fireplaces, Vented. 

908.1 Prohibited Installations. Vented gas fireplaces 
shall not be installed in bathrooms or bedrooms 
unless the appliance is listed and the bedroom or 
bathroom has the required volume in accordance with 
Section 701.2. 

Exception: Direct-vent gas fireplaces. 

908.2 Installation. The installation of vented gas 
fireplaces shall comply with the following require- 
ments: 

(A) Listed vented gas fireplaces shall be installed in 
accordance with their listing and the 
manufacturers' instructions and where installed 
in or attached to combustible material shall be 
specifically listed for such installation. 

(B) Unlisted vented gas fireplaces shall not be 
installed in or attached to combustible material. 
They shall have a clearance at the sides and rear 
of not less than eighteen (18) inches (460 mm). 
Combustible floors under unlisted vented gas 
fireplaces shall be protected in an approved 
manner. Unlisted appliances of other than the 
direct-vent type shall be equipped with a draft 
hood and shall be properly vented in accordance 
with Chapter 8. Appliances that use metal, asbestos, 
or ceramic material to direct radiation to the 
front of the appliance shall haye a clearance of 
thirty-six (36) inches (910mm) in front and, if 
constructed with a double back of metal or 



ceramic, shall be installed with a minimum 
clearance of eighteen (18) inches (460 mm) at the 
sides and twelve (12) inches (300 mm) at the rear. 

(C) Panels, grilles, and access doors that are required 
to be removed for normal servicing operations 
shall not be attached to the building. 

(D) Direct-vent gas fireplaces shall be installed with 
the vent-air intake terminal in the outdoors and in 
accordance with the manufacturers' instructions. 
[NFPA 54:9.7.2] 

908.3 Combustion and Circulating Air. 

Combustion and circulating air shall be provided in 
accordance with Section 701.0. [NFPA 54:9.7.3] 

909.0 Non-Recirculating Direct Gas-Fired 
Industrial Air Heaters. 

909.1 Application. Direct gas-fired industrial air 
heaters of the non-recirculating type shall be listed in 
accordance with ANSI Z83.4/CSA 3.7 Non- 
Recirculating Direct Gas-Fired Industrial Air Heaters. 
[NFPA 54:10.8.1] 

909.2 Proliibited Installations. 

(A) Non-recirculating direct gas-fired industrial air 
heaters shall not serve any area containing 
sleeping quarters. 

(B) Non-recirculating direct gas-fired industrial air 
heaters shall not recirculate room air. [NFPA 54: 
9.8.2] 

909.3 Installation. Installation of direct gas-fired 
industrial air heaters shall comply with the following 
requirements: 

(A) Non-recirculating direct gas-fired industrial air 
heaters shall be installed in accordance with the 
manufacturers' instructions. 

(B) Non-recirculating direct gas-fired industrial air 
heaters shall be installed only in industrial or 
commercial occupancies. 

(C) Non-recirculating direct gas-fired industrial air 
heaters shall be permitted to provide fresh air 
ventilation. 

(D) Non-recirculating direct gas-fired industrial air 
heaters shall be provided with access for 
removal of burners; replacement of motors, 
controls, filters, and other working parts; and for 
adjustment and lubrication of parts requiring 
maintenance. [NFPA 54:9.8.3] 

909.4 Clearance from Combustible IVIaterials. 

Non-recirculating direct gas-fired industrial air 
heaters shall be installed with a clearance from 
combustible materials of not less than that shown on 



153 



909.4-910.6 



2007 CALIFORNIA MECHANICAL CODE 



the rating plate and the manufacturers' instructions. 
[NFPA 54:9.8.4] 

909.5 Air Supply. All air to the non-recirculating 
direct gas-fired industrial air heater shall be ducted 
directly from outdoors. Where outside-air dampers 
or closing louvers are used, they shall be verified to 
be in the open position prior to main burner operation. 
[NFPA 54:9.8.5] 

909.6 Atmospheric Vents or Gas Reliefs or 
Bleeds. Non-recirculating direct gas-fired industrial 
air heaters with valve train components equipped 
with atmospheric vents, gas reliefs, or bleeds shall 
have their vent lines, gas reliefs, or bleeds lead to a 
safe point outdoors. Means shall be employed on 
these lines to prevent water from entering and to 
prevent blockage from insects and foreign matter. 
An atmospheric vent line shall not be required to be 
provided on a valve train component equipped with 
a listed vent limiter. [NFPA 54:9.8.6] 

909.7 Relief Openings. The design of the 
installation shall include adequate provisions to 
permit the non-recirculating direct gas-fired 
industrial air heater to operate at its rated airflow 
without overpressurizing the space served by the 
heater by taking into account the structure's 
designed infiltration rate, properly designed relief 
openings, or an interlocked powered exhaust system, 
or a combination of these methods. 

(A) The structure's designed infiltration rate and the 
size of relief opening(s) shall be determined by 
approved engineering methods. 

(B) Louver or counterbalanced gravity damper relief 
openings shall be permitted. Where motorized 
dampers or closeable louvers are used, they shall 
be proved to be in their open position prior to 
main burner operation. [NFPA 54:9.8.7] 

909.8 Purging. Inlet ducting, when used, shall be 
purged with at least four air changes prior to an 
ignition attempt. [NFPA 54:9.8.8] 

910.0 Recirculating Direct Gas-Fired Industrial 
Air Heaters. 

910.1 Application. Direct gas-fired industrial air 
heaters of the recirculating type shall be designed 
certified to be in compliance with the Standard for 
Recirculating Direct Gas-Fired Industrial Air 
Heaters, ANSI Z83.18. Unlisted direct gas-fired 
industrial air heaters of the recirculating type shall 
not be installed. [NFPA 54:9.9.1] 

910.2 Prohibited Installations. 

(A) Recirculating direct gas-fired industrial air 
heaters shall not serve any area containing 
sleeping quarters. 

(B) Recirculating direct gas-fired industrial air 



heaters shaU not recirculate room air in buildings 
that contain flammable solids, liquids, or gases, 
explosive materials, or substances that can 
become toxic when exposed to flame or heat. 
[NFPA 54:9.9.2] 

910.3 Installation. Installation of direct gas-fired 
industrial air heaters shall comply with the following 
requirements: 

(A) Recirculating direct gas-fired industrial air 
heaters shall be installed in accordance with the 
manufacturer's instructions. 

(B) Recirculating direct gas-fired industrial air 
heaters shall be installed only in industrial or 
commercial occupancies. 

(0) Recirculating direct gas-fired industrial air 
heaters shall be permitted to provide fresh air 
ventilation only for the amotmt that exceeds the 
minimum ventilation air specified on the 
heater's rating plate to maintain the combustion 
level created by the heater in the space being 
served by the heater below 25 ppm for carbon 
monoxide, 3 ppm for nitrogen dioxide, and 5000 
ppm for carbon dioxide. Where gas-powered 
fork trucks or other fossU-fueled equipment are 
utilized in the conditioned space, additional 
ventilation requirements for the facility must be 
addressed separately. 

(D) Recirculating direct gas-fired industrial air 
heaters shall be provided with access for 
removal of burners; replacement of motors, 
controls, filters, and other working parts; and for 
adjustment and lubrication of parts requiring 
maintenance. [NFPA 54:9.9.3] 

910.4 Clearance from Combustible Materials. 

Recirculating direct gas-fired industrial air heaters shall 
be installed with a clearance from combustible 
materials of not less than that shown on the rating plate 
and the manufacturer's instructions. [NFPA 54:9.9.4] 

910.5 Air Supply. Ventilation air to the recirculating 
direct gas-fired industrial air heater shall be ducted 
directly from outdoors. Air to the recirculating direct 
gas-fired industrial air heater in excess of the 
minimum ventilation air specified on the heater's 
rating plate shall be taken from the building, ducted 
directly from outdoors, or a combination of both. 
Where outside-air dampers or closing louvers are 
used, they shall be verified to be in the open position 
prior to main burner operation. [NFPA 54:9.9.5] 

910.6 Atmospheric Vents or Gas Reliefs or 
Bleeds. Recirculating direct gas-fired industrial air 
heaters with valve train components equipped with 
atmospheric vents, gas reliefs, or bleeds shall have 
their vent lines, gas reliefs, or bleeds lead to a safe 



154 



INSTALLATION OF SPECIFIC EQUIPMENT 



Table 9-1 -910.8 



TABLE 9-1 

Clearances to Combustible Material for Unlisted Furnaces, Boilers, and Air Conditioners Installed in 

Rooms That Are Large in Comparison with the Size of Equipment. 

Minimum Clearance (in.) 



Equipment 



Above and 
Sides of 
Furnace 
Plenum 



Top of Jacket Sides 
Boiler and Rear 



Front 



Draft Hood and 

Barometric Single-Wall Vent 
Draft Regulator Connector 



I Automatically fired, forced 
air or gravity system, 
equipped with temperature 
limit control that cannot be 
set higher than 250°F (121°C) 



18 



18 



Automatically fired heating 
boilers - steam boUers 
operating at not over 15 psi 
(103 kPa) and hot water 
boilers operating at 250°F 
(lai-Oorless 



18 



18 



18 



in Central heating boilers and 
furnaces, other than in I or II 


18 


18 


18 


18 


18 


18 


IV Air-conditioning equipment 


18 


18 


18 


18 


18 


18 



TABLE 9-2 
Free Opening Area of Chimney Damper for Venting Flue Gases from Unlisted Decorative Appliances 
■ for Installation in Vented Fireplaces. 





Minimum Permanent Free Ooenine (in.^)* 


Chimney 


8 


13 


20 


29 


39 


51 


64 


Height 










(ft.) 




Appliance Input Rating (Btu/h) 






6 


7,800 


14,000 


23,200 


34,000 


46,400 


62,400 


80,000 


8 


8,400 


15,200 


25,200 


37,000 


50,400 


68,000 


86,000 


10 


9,000 


16,800 


27,600 


40,400 


55,800 


74,400 


96,400 


15 


9,800 


18,200 


30,200 


44,600 


62,400 


84,000 


108,800 


20 


10,600 


20,200 ' 


32,600 


50,400 


68,400 


94,000 


122,200 


30 


11,200 


21,600 


36,600 


55,200 


76,800 


105,800 


138,600 ■ 



For SI units, 1 ft = 0.305 m; 1 in.^ = 645mm^; 1,000 Btu/h = 0.293 kW 

*The first six minimum permanent free openings (8 in.' to 51 in.') correspond approximately to the cross-sectional areas of chimneys having diameters 

of 3 in. through 8 in., respectively. The 64 in.' opening corresponds to the cross-sectional area of standard 8 in. x 8 in. chimney tile. 



point outdoors. Means shall be employed on these 
lines to prevent water from entering and to prevent 
blockage from insects and foreign matter. An 
atmospheric vent line shall not be required to be 
provided on a valve train component equipped with 
a listed vent limiter. [NFPA 54:9.9.6] 

910.7 Relief Openings. The design of the 
installation shall include adequate provisions to 
permit the recirculating direct gas-fired industrial air 
heater to operate at its rated airflow without 
overpressurizing the space served by the heater by 
taking into account the structure's designed 



infiltration rate, properly designed relief openings or 
an interlocked powered exhaust system, or a 
combination of these methods. 

(A) The structure's designed infiltration rate and the 
size of relief opening(s) shall be determined by 
approved engineering methods. 

(B) Louver or counterbalanced gravity relief 
openings shall be permitted. Where motorized 
dampers or closeable louvers are used, they shall 
be proved to be in their open position prior to 
main burner operation. [NFPA 54:9.9.7] 

910.8 Purging. Inlet ducting, when used, shall be 



155 



910.8-911.8 



2007 CALIFORNIA MECHANICAL CODE 



purged with at least four air changes prior to an 
ignition attempt. [NFPA 54:9.9.8] 

911.0 Duct Furnaces. 

91 1 .1 Clearances. The installation of duct furnaces 
shall comply with the following clearance 
requirements: 

(A) Listed duct furnaces shall be installed with 
clearances of at least six (6) inches (150 mm) between 
adjacent walls, ceilings, and floors of combustible 
material and the furnace draft hood. Furnaces 
listed for installation at lesser clearances shall be 
installed in accordance with their listings. In no 
case shall the clearance be such as to interfere 
with combustion air and accessibility. (See 
Sections 305.1 and 701.0.) 

(B) Unlisted duct furnaces shall be installed with 
clearances to combustible material in accordance 
with the clearances specified for unlisted 
furnaces and boilers in Table 9-1. Combustible 
floors under unlisted duct furnaces shall be 
protected in an approved manner. [NFPA 54:9.10.1] 

911.2 Erection of Equipment. Duct furnaces shall 
be erected and firmly supported in accordance with 
the manufacturers' instructions. [NFPA 54:9.10.2] 

911.3 Access Panels. The ducts cormected to duct 
furnaces shall have removable access panels on both 
the upstream and downstream sides of the furnace. 
[NFPA 54:9.10.3] 

911.4 Location of Draft Hoods and Controls. The 

controls, combustion-air inlet, and draft hoods for 
duct furnaces shall be located outside the ducts. The 
draft hood shall be located in the same enclosure 
from which combustion air is taken. [NFPA 54:9.10.4] 

911.5 Circulating Air. Where a duct furnace is 
installed so that supply ducts carry air circulated by 
the furnace to areas outside the space containing the 
furnace, the return air shall also be handled by a 
duct(s) sealed to the furnace casing and terminating 
outside the space containing the furnace. The duct 
furnace shall be installed on the positive-pressure 
side of the circulating air blower. [NFPA 54:9.10.5] 

911.6 Duct Furnaces Used with Refrigeration 
Systems. 

(A) A duct furnace shall not be installed in 
conjunction with a refrigeration coil where 
circulation of cooled air is provided by the 
blower. 

Exception: Where the blower has sufficient 
capacity to overcome the external static 
resistance imposed by the duct system, 
furnace, and the cooling coil and the air 
throughput necessary for heating or cooling, 
whichever is greater. 



(B) Duct furnaces used in conjvmction with cooling 
equipment shall be installed in parallel with or 
on the upstream side of cooling coils to avoid 
condensation within heating elements. With a 
parallel flow arrangement, the dampers or other 
means used to control the flow of air shall be 
sufficiently tight to prevent any circulation of 
cooled air through the unit. 

Exception: Where the duct furnace has been 
specifically listed for downstream 
installation. 

(C) Where duct furnaces are to be located upstream 
from cooling units, the cooling unit shall be so 
designed or equipped as to not develop excessive 
temperatures or pressures. 

(D) Where a duct furnace is installed downstream of 
an evaporative cooler or air washer, the heat 
exchanger shall be constructed of corrosion- 
resistant materials. Stainless steel, ceramic- 
coated steel, and an aluminum-coated steel in 
which the bond between the steel and the 
aluminum is an iron-aluminum alloy are 
considered to be corrosion resistant. Air washers 
operating with chilled water that deliver air 
below the dew point of the ambient air at the 
equipment are considered as refrigeration 
systems. [NFPA 54:9.10.6] 

911.7 Installation in Commercial Garages and 
Aircraft Hangars. Duct furnaces installed in garages 
for more than three motor vehicles or in aircraft 
hangars shall be of a listed type and shall be installed 
in accordance with Sections 911.8 and 911.9. [NFPA 
54:9.10.7] 

911.8 Installation in Commercial Garages. 

911.8.1 Parking Structures. Gas utilization 
equipment installed in enclosed, basement, and 
undergroimd parking structures shall be installed 
in accordance with NFPA 88A, Standard for 
Parking Structures. 

91 1 .8.2 Repair Garages. Gas utilization equip- 
ment installed in repair garages shall be installed 
in a detached buUding or room, separated from 
repair areas by walls or partitions, floors, or floor- 
ceiling assemblies that are constructed so as to 
prohibit the transmission of vapors and having a 
fire resistance rating of not less than one (1) hour, 
and that have no openings in the wall separating 
the repair area within eight (8) feet (2.4 m) of the 
floor. Wall penetrationB shall be firestopped. Air 
for combustion purposes shall be obtained from 
outside the building. The heating room shall not 
be used for the storage of combustible materials. 



156 



INSTALLATION OF SPECIFIC EQUIPMENT 



911.8-912.9 



Exceptions: 

(1) Overhead heaters where installed not 
less than eight (8) feet (2.4 m) above the 
floor shall be permitted. 

(2) Heating equipment for vehicle repair 
areas where there is no dispensing or 
transferring of Class I or Class II 
flammable or combustible liquids or 
liquefied petroleum gas shall be 
installed in accordance with NFPA 
30A, Code for Motor Fuel Dispensing 
Facilities and Repair Garages. 

911.9 Installation In Aircraft Hangars. Heaters in 
aircraft hangars shall be installed in accordance with 
NFPA 409, Standard on Aircraft Hangars. 

912.0 Floor Furnaces. 

912.1 Installation. The installation of floor furnaces 
shall comply with the following requirements: 

(A) Listed floor furnaces shall be installed in 
accordance with their listing and the 
manufacturers' instructions. 

(B) UnJisted floor furnaces shall not be installed in 
combustible floors. 

(C) Thermostats controlling floor furnaces shall not 
be located in a room or space that can be 
separated from the room or space in which the 
register of the floor furnace is located. [NFPA 
54:9.11.1] 

912.2 Temperature Limit Controls. 

(A) Listed automatically operated floor furnaces 
shall be equipped with temperature limit 
controls. 

(B) Unlisted automatically operaited floor furnaces 
shall be equipped with a temperature limit 
control arranged to shut off the flow of gas to the 
burner in the event the temperature at the 
warm-air outlet register exceeds 350°F (177°C) 
above room temperature. [NFPA 54:9.11.2] 

912.3 Combustion and Circulating Air. 

Combustion and circulating air shall be provided in 
accordance with Section 701.0. [NFPA 54: 9.11.3] ' 

912.4 Placement.. The following provisions apply to 
furnaces that serve one story. 

(A) Floors. Floor furnaces shall not be installed in 
the floor of any doorway, stairway landing, 
aisle, or passageway of any enclosure, public or 
priva;te, or in an exitway from any such room or 
space. 

(B) Walls and Corners. The register of a floor 



furnace with a horizontal warm-air outlet shall 
not be placed doser than six (6) inches (150 mm) from 
the nearest wall. A distance of at least 18 in. (460 
mm) from two adjoining sides of the floor 
furnace register to walls shall be provided to 
eliminate the necessity of occupants walking 
over the warm-air discharge. The remaining 
sides shall be a minimum of sb< (6) inches (150 mm) 
from a wall. Wall-register models shall not be 
placed closer than 6 in. (150 mm) to a corner. 

(C) Draperies. The furnace shall be placed so that a 
door, drapery, or similar object cannot be nearer 
than twelve (12) inches (300 mm) to any portion of the 
register of the furnace. [NFPA 54:9.11.4] 

912.5 Bracing. The space provided for the furnace 
shall be framed with doubled joists and with headers 
not lighter than the joists. [NFPA 54:9.11.5] 

912.6 Support. Means shall be provided to support 
the furnace when the floor register is removed. 
[NFPA 54:9.11.6] 

91 2.7 Clearance. The lowest portion of the floor furnace 
shall have at least a six (6) inch (150 mm) clearance from 
the general ground level. A reduced clearance to a 
minimum of two (2) inches (50 mm) is permitted, 
provided the lower six (6) inches (150 mm) portion of the 
floor furnace is sealed by the manufacturer to prevent 
entrance of water. Where these clearances are not 
present, the ground below and to the sides shall be 
excavated to form a "basin-like" pit under the furnace so 
that the required clearance is provided beneath the 
lowest portion of the furnace. A twelve (12) inch (300 
mm) clearance shall be provided on all sides except the 
control side, that shall have an eighteen (18) inch (460 
mm) clearance. [NFPA 54:9.11.7] 

91 2.8 Access. The space in which any floor furnace 
is installed shall be accessible by an opening in the 
foundation not less than twenty-four (24) inches x 
eighteen (18) inches (610 mm x 460 mm) or by a 
trapdoor not less than twenty-four (24) inches x 
twenty-four (24) inches (610 mm x 610 mm) in any 
cross-section thereof, and a passageway not less than 
twenty-four (24) inches x eighteen (18) inches (610 
mm X 460 imn) in any cross-section thereof. [NFPA 
54:9.11.8] 

912.9 Seepage Pan. Where the excavation exceeds 
twelve (12) inches (300 mm) in depth or water 
seepage is likely to collect, a watertight copper pan, 
concrete pit, or other suitable material shall be used, 
unless adequate drainage is provided or the 
equipment is sealed by the manufacturer to meet this 
condition. A copper pan shall be made of not less 
than 16 oz./ft.^(4.9 kg/m^) sheet copper. The pan 
shall be anchored in place so as to prevent floating, 
and the walls shall extend at least four (4) inches (100 
mm) above the ground level with at least six (6) 



157 



912.9-913.3 



2007 CALIFORNIA MECHANICAL CODE 



inches (150 mm) clearance on all sides, except the 
control side, which shall have at least eighteen (18) 
inches (460 mm) clearance. [NFPA 54:9.11.9] 

912.10 Wind Protection. Floor furnaces shall be 
protected, where necessary, against severe wind 
conditions. [NFPA 54: 9.11.10] 

912.11 Upper-Floor Installations. Listed floor 
furnaces shall be permitted to be installed in an 
upper floor, provided the furnace assembly projects 
below into a utility room, closet, garage, or similar 
nonhabitable space. In such installations, the floor 
furnace shall be enclosed completely (entirely 
separated from the nonhabitable space) with means 
for air intake to meet the provisions of Section 701.0, 
with access for servicing, the mininium furnace 
clearances of six (6) inches (150 mm) to all sides and 
bottom, and with the enclosure constructed of 
Portland cement plaster or metal lath or other 
noncombustible material. [NFPA 54:9.11.11] 

912.12 First Floor Installation. Listed floor furnaces 
installed in the first or ground floors of buildings 
shall not be required to be enclosed unless the 
basements of these buildings have been converted to 
apartments or sleeping quarters, in which case the 
floor furnace shall be enclosed as specified for upper 
floor installations and shall project into a non- 
habitable space. [NFPA 54:9.11.12] 

913.0 Food Service Equipment, Floor iVIounted. 

913.1 Clearance for Listed Equipment. Listed floor- 
motinted food service equipment, such as ranges for 
hotels and restaurants, deep-fat fryers, unit broilers, 
gas-fired kettles, steam cookers, steam generators, and 
baking and roasting ovens, shall be installed at least 
six (6) inches (150 mm) from combustible material 
except that at least a two (2) inch (50 mm) clearance 
shall be maintained between a draft hood and 
combustible material. Floor-mounted food service 
equipment listed for installation at lesser clearances 
shall be installed ki accordance with its listing and the 
manufacturer's instructions. Equipment designed and 
marked, "For use only in noncombustible locations," 
shall not be installed elsewhere. [NFPA 54:9.12.1] 

913.2 Clearance for Unlisted Equipment. Unlisted 
floor-mounted food service equipment shall be 
installed to provide a clearance to combustible 
material of not less than eighteen (18) inches (460 
mm) from the sides and rear of the equipment and 
from the vent connector and not less than forty-eight 
(48) inches (1.2 m) above cooking tops and at the 
front of the equipment. 

Clearances for unlisted equipment installed in 
partially enclosed areas such as alcOves shall not be 
reduced. Where clearances for unlisted equipment 
installed in rooms that are not partially enclosed are 



reduced, the combustible material or the equipment 
shall be protected as described in Table 5-3. [NFPA 
54:9.12.2] 

913.3 Mounting on Combustible Floor. 

(A) Listed floor-mounted food service equipment 
that is listed specifically for installation on floors 
constructed of combustible material shall be 
permitted to be motmted on combustible floors 
in accordance with its listing and the manu- 
facturer's instructions. 

(B) Floor-mounted food service equipment that is 
not listed for mounting on a combustible floor 
shall be mounted in accordance with Section 
913.4 or be mounted in accordance with one of 
the following: 

(1) Where the equipment is set on legs that 
provide not less than 18 in. (460 mm) open 
space under the base of the equipment or 
where it has no burners and no portion of 
any oven or broiler within 18 in. (460 mm) of 
the floor, it shall be permitted to be mounted 
on a combustible floor without special floor 
protection, provided there is at least one 
sheet metal baffle between the burner and 
the floor. 

(2) Where the equipment is set on legs that 
provide not less than eight (8) inches (200 mm) 
open space under the base of the equipment, 
it shall be permitted to be mounted on 
combustible floors, provided the floor xmder 
the equipment is protected with not less 
than 3/8 inch (9.5 mm) insulating millboard 
covered with sheet metal not less than 
0.0195 inch (0.5 mm) thick. The preceding 
specified floor protection shall extend not 
less than six (6) inches (150 mm) beyond the 
equipment on all sides. 

(3) Where the equipment is set on legs that 
provide not less than four (4) inches (100 mm) 
xmder the base of the eqmpment, it shall be 
permitted to be mounted on combustible 
floors, provided the floor under the 
equipment is protected with hollow 
masonry not less than fouor (4) inches (100 mm) 
in thickness covered with sheet metal not 
less than 0.0195 inch (0.5 mm) thick. Such 
masonry courses shall be laid with ends 
unsealed and joints matched in such a way 
as to provide for free circulation of air 
through the masonry. 

(4) Where the equipment does not have legs at 
least four (4) indies (100 mm) high, it shall be 
permitted to be mounted on combustible 
floors, provided the floor under the 
equipment is protected by two courses of 



158 



INSTALLATION OF SPECIFIC EQUIPMENT 



913.3-916.1 



four (4) inch (100 mm) hollow clay tile, or 
equivalent, with courses laid at right angles 
and with ends unsealed and joints matched 
in such a way as to provide for free 
circulation of air through such masonry 
courses, and covered with steel plate not less 
than 3/16 inch (4.8 mm) in thickness. [NFPA 
54:8.12.3] 

913.4 Mounting on Noncombustible Floor. Listed 
floor-mounted food service equipment that is 
designed and marked, "For use only in non- 
combustible locations, "shall be mounted on floors of 
noncombustible construction with noncombustible 
flooring and surface finish and with no combustible 
material against the underside thereof, or on 
noncombustible slabs or arches having no com- 
bustible material against the underside thereof. Such 
construction shall in all cases extend not less than 
twelve (12) inches (300 mm) beyond the equipment 
on all sides. [NFPA 54:9.12.4] 

913.5 Combustible Material Adjacent to Cooking 
Top. Any portion of combustible material adjacent to 
a cooking top section of a food service range, even 
though listed for close-to-waH installation, that is not 
shielded from the waU by a high shelf, warming closet, 
and so on, shall be protected as specified in Section 
913.2 for a distance of at least two (2) feet (0.6 m) above 
the surface of the cooking top. [NFPA 54:9.12.5] 

913.6 For Use withi Casters. Floor-mounted 
equipment with casters shall be listed for such 
construction and shall be installed in accordance 
with their listing and the accompanying instructions 
for limiting the movement of the equipment to 
prevent strain on the connection. [NFPA 54:9.12.6] 

913.7 Level Installation. Floor-mounted food 
service equipment shall be installed level on a firm 
foundation. [NFPA 54:9.12.7] 

913.8 Ventilation. Means shall be provided to 
properly ventilate the space in which food service 
equipment is installed to permit proper combustion 
of the gas. [NFPA 54:9.12.8] 

914.0 Food Service Equipment Counter Appliances. 

914.1 Vertical Clearance. A vertical distance of not 
less than forty-eight (48) inches (1.2 m) shall be 
provided between the top of all food service hot 
plates and griddles and combustible material. [NFPA 
54:9.13.1] 

914.2 Clearance for Listed Appliances. Listed 
food service counter appliances such as hot plates 
and griddles, food and dish warmers, and coffee 
brewers and urns, where installed on combustible 
surfaces, shall be set on their own bases or legs and 
shall be installed with a minimum horizontal 



clearance of six (6) inches (150 mm) from combustible 
material, except that at least a two (2) inch (50 mm) 
clearance shall be maintained between a draft hood 
and combustible material. Food service counter 
appliances listed for installation at lesser clearances 
shall be installed in accordance with their listing and 
the manufacturers' instructions. [NFPA 54:9.13.2] 

914.3 Clearance for Unlisted Appliances. Unlisted 
food service hot plates and griddles shall be installed 
with a horizontal clearance from combustible 
material of not less than eighteen (18) inches (460 
mm). Unlisted gas food service counter appliances, 
including coffee brewers and urns, waffle bakers, 
and hot water immersion sterilizers, shall be 
installed with a horizontal clearance from 
combustible material of not less than twelve (12) 
inches (300 mm). Reduced clearances for gas food 
service counter appliances shall be in accordance 
with Table 5-3. Unlisted food and dish warmers shall 
be installed with a horizontal clearance from 
combustible material of not less than six (6) inches 
(150 mm). [NFPA 54:9.13.3] 

914.4 Mounting of Unlisted Appliances. Unlisted 
food service counter appliances shall not be set on 
combustible material unless they have legs that 
provide not less than four (4) inches (100 mm) of open 
space below the burners and the combustible surface 
is protected with insulating millboard at least 1 /4 inch 
(6.4 mm) thick covered with sheet metal not less than 
0.0122 inch (0.3 mm) thick, or with equivalent 
protection. [NFPA 54:9.13.4] 

915.0 Hot Plates and Laundry Stoves. 

(A) Listed domestic hot plates and laundry stoves 
installed on combustible surfaces shall be set on 
their own legs or bases. They shall be installed 
with minimum horizontal clearances of six (6) 
inches (150 mm) from combustible material. 

(B) Unlisted domestic hot plates and laundry stoves 
shall be installed with horizontal clearances to 
combustible material of not less than twelve (12) 
inches (300 mm). Combustible surfaces under 
unlisted domestic hot plates and laundry stoves 
shall be protected in an approved manner. 

(C) The vertical distance between tops of all 
domestic hot plates and laundry stoves and 
combustible material shall be at least thirty (30) 
inches (760 mm). [NFPA 54:9.14] 

916.0 Household Cooking Appliances. 

916.1 Floor-Mounted Units. 

(A) Clearance from Combustible Material. 

The clearances specified as follows shall not 



159 



916.1 -Table 9-3 



2007 CALIFORNIA MECHANICAL CODE 



interfere with combustion air, accessibility 
for operation, and servicing. 

(1) Listed floor-mounted household 
cooking appliances, where installed 
on combustible floors, shall be set 
on their own bases or legs and shall 
be installed in accordance with their 
listing and the manufacturers' 
instructions. 

(2) Listed household cooking appliances 
with listed gas room heater sections 
shall be installed so that the warm- 
air discharge side shall have a mini- 
mum clearance of eighteen (18) inches 
(460 mm) from adjacent combustible 
material. A minimum clearance of 
thirty (36) inches (910 mm) shall be 
provided between the top of the heater 
section and the bottom of cabinets. 

(3) Listed household cooking appliances 
that include a solid-or liquid fuel- 
burning section shall be spaced 
from combustible material and 
otherwise installed in accordance with 
the standards applying to the supple- 
mentary fuel section of the appliance. 

(4) Uiilisted floor-mounted household 
cooking appliances shall be installed 
with at least six (6) inches (150 mm) 
clearance at the back and sides to 
combustible material. Combustible 
floors under unlisted appliances 
shall be protected in an approved 
manner. 

(B) Vertical Clearance Above Cooking Top. 

Household cooking appliances shall have a 
vertical clearance above the cooking top of 
not less than thirty (30) inches (760 mm) to 
combustible material or metal cabinets. A 
minimum clearance of twenty-four (24) 
inches (610 mm) is permitted when one of 
the following is installed: 

(1) The underside of the combustible 
material or metal cabinet above the 
cooking top is protected with not less 
than 1/4 inch (6.4 mm) insulating 
millboard covered with sheet metal not 
less than 0.0122 inch (0.3 mm) thick. 

(2) A metal ventilating hood of sheet metal 
not less than 0.0122 inch (0.3 mm) thick 
is installed above the cooking top with a 
clearance of not less than 1/4 inch (6.4 
mm)between the hood and the underside 
of the combustible material or metal 
cabinet, and the hood is at least as wide 
as the appliance and is centered over 
the appliance. 



(3) A listed cooking appliance or microwave 
oven is installed over a listed cooking 
appliance and wiU conform to the terms of 
the upper appliance's listing and the manu- 
facturers' instructions. [NFPA 54:9.15.1] 

916.2 Built-in Units. 

(A) Installation. Listed built-in household cooking 
appliances shall be installed in accordance with 
their listing and the manufacturers' instructions. 
The installation shall not interfere with 
combustion air, accessibility for operation, and 
serving. Unlisted built-in household cooking 
appliances shall not be installed in or adjacent 
to combustible material. 

(B) Vertical Clearance. Built-in top (or surface) 
cooking appliances shall have a vertical clearance 
above the cooking top of not less than thirty (30) 
inches (760 mm) to combustible material or 
metal cabinets. A minimvun clearance of twenty- 
four (24) inches (610 mm) is permitted when one 
of the following is installed: 

(1) The underside of the combustible material 
or metal cabinet above the cooking top is 
protected with not less than 1/4 inch (6.4 mm) 
insulating millboard covered with sheet 
metal not less than 0.0122 inch (0.3 mm) thick. 

(2) A metal ventilating hood of sheet metal not 
less than 0.0122 inch (0.3 mm) thick is 
installed above the cooking top with a 
clearance of not less than 1/4 inch (6.4 mm) 
between the hood and the Underside of 
the combustible material or metal cabinet, 
and the hood is at least as wide as the 
appliance and is centered over the appliance. 

(3) A listed cooking appliance or microwave 
oven is installed over a listed cooking 
appliance and will coriform to the terms of 
the upper appliance's listing and the 
manufacturers' instructions. 

(C) Horizontal Clearance. The minimum horizontal 
distance from the center of the burner head(s) of 

TABLE 9-3 Clearances for Unlisted Outdoor Open- 
Flame Illuminating Appliances 



Flame Height 


Minimum Clearance from 


Above Burner 


Combustible Material (ft.)* 


Head 










(in.) 


Horizontal 


Vertical 


12 


2 


6 


18 


3 


8 


24 


3 


10 


30 


4 


12 



For SI units, 1 in. =25.4 mm; 1 ft. = 0.305 m. 

* Measured from the nearest portion of the burner head. 



160 



INSTALLATION OF SPECIFIC EQUIPMENT 



916.2-919.2 



a listed top (or surface) cooking appliance to 
vertical combustible walls extending above the 
top panel shall be riot less than that distance 
specified by the permanent marking on the 
appliance. 

(D) Level Installation. Built-in household cooking 
appliances shall be installed so that the cooking 
top, broiler pan, or oven racks are level. [NFPA 
54:9.15.2] 

917.0 Illuminating Appliances. 

917.1 Clearances for Listed Appliances. Listed 
illuminating appliances shall be installed in 
accordance with their listing and the manufacturers' 
instructions. [NFPA 54:9.16.1] 

917.2 Clearances for Unlisted Appliances. 

(A) Enclosed Type. 

(1) Unlisted enclosed illuminating appliances 
installed outdoors shall be installed with 
clearances in any direction from combustible 
material of not less than twelve (12) inches 
(300 mm). 

(2) Unlisted enclosed illuminating appliances 
installed indoors shall be installed with 
clearances in any direction from combustible 
material of not less than eighteen (18) inches 
(460 mm). 

(B) Open-Flame Type. 

(1) Unlisted open-flame illuminating appliances 
installed outdoors shall have clearances 
from combustible material not less than that 
specified in Table 9-3. The distance from 
ground level to the base of the burner shall 
be at least seven (7) feet (2 m) where 
installed within two (2) feet (0.6 m) of 
walkways. Lesser clearances shall be 
permitted to be used where acceptable to the 
Authority Having Jurisdiction. 

(2) Unlisted open-flame illuminating appliances 
installed outdoors shall be equipped with a 
limiting orifice or other limiting devices that 
will maintain a flame height consistent with 
the clearance from combustible material, as 
given in Table 9-3. 

(3) Appliances designed for flame heights in 
excess of thirty (30) inch (760 mum) shall be 
permitted to be installed if acceptable to the 
Authority Having Jurisdiction. Such 
appliances shall be equipped with a safety 
shutoff device or automatic ignition. 

(4) Unlisted open-flame flluminating appliances 
installed indoors shall have clearances from 



combustible material acceptable to the 
Authority Having Jtmsdidion. [NFPA 54:9.16.2] 

917.3 Mounting on Buildings. Illuminating 
appliances designed for wall or ceiling mounting shall 
be securely attached to substantial structures in such a 
manner that they are not dependent on the gas piping 
for support. [NFPA 54:9.16.3] 

917.4 Mounting on Posts, flluminating appliances 
designed for post mounting shall be securely and 
rigidly attached to a post. Posts shall be rigidly 
mounted. The strength and rigidity of posts greater 
than three (3) feet (0.9 m) in height shall be at least 
equivalent to that of a 2-1/2 inch (64 mm) diameter 
post constructed of 0.064 in. (1.6 mm) thick steel or a 
1 in. Schedule 40 steel pipe. Posts three (3) feet (0.9 
m) or less in height shall not be smaller than a 3/4 
inch Schedule 40 steel pipe. Drain openings shall be 
provided near the base of posts where there is a 
possibility of water collecting inside them. [NFPA 
54:9.16.4] 

917.5 Gas Appliance Pressure Regulators. Where 
a gas appliance pressure regulator is not supplied 
with an illuminating appliance and the service line is 
not equipped with a service pressure regulator, an 
appliance pressure regulator shall be installed in the 
line serving one or more illuminating appliances. 
[NFPA 54:9.16.5] 

918.0 Incinerators, Commercial-Industrial. 

Commercial-industrial-type incinerators shall be 
constructed and installed in accordance with NFPA 82, 
Standard on Incinerators and Waste and Linen 
Handling Systems and Equipment. [NFPA 54:9.17] 

919.0 Infrared Heaters. 

919.1 Support. Suspended-type infrared heaters 
shall be fixed in position independent of gas and 
electric supply lines. Hangers and brackets shall be 
of noncombustible material. Heaters subject to 
vibration shall be provided with vibration-isolating 
hangers. [NFPA 54:9.18.1] 

919.2 Clearance. The installation of iiifrared heaters 
shall comply with the following clearance 
requirements: 

(A) Listed heaters shall be installed with clearances 
from combustible material in accordance with 
their listing and the manufacturers' instructions. 

(B) Unlisted heaters shall be installed in accordance 
with clearances from combustible material 
acceptable to the Authority Having Jurisdiction. 

(C) In locations used for the storage of combustible 



161 



919.2-923.2 



2007 CALIFORNIA MECHANICAL CODE 



materials, signs shall be posted to specify the 
maximum permissible stacking height to 
maintain required clearances from the heater to 
the combustibles. [NFPA 54:9.18.2] 

919.3 Combustion and Ventilation Air. 

(A) Where unvented infrared heaters are used, 
natural or mechanical means shall be provided 
to supply and exhaust at least 4 ft.Vmin/ 1,000 
Btu/h (0.38 mVmin/kW) input of installed 
heaters. 

(B) Exhaust openings for removing flue products 
shall be above the level of the heaters. [NFPA 
54:9.18.3] 

919.4 Installation in Commercial Garages and 
Aircraft Hangars. Overhead heaters installed in 
garages for more than three motor vehicles or in 
aircraft hangars shall be of a listed tj^e and shall be 
installed in accordance with Sections 911.8 and 911.9. 
[NFPA 54:9.18.4] 

920.0 Open-Top Broiler Units 

Listed open-top broiler units and hoods shall be 
installed in accordance with their listing and the 
mantifacturers' installation instructions. 

An exhaust duct and fan having a minimum 
capacity of 100 cfm per square foot (508 L/s/m^) of 
hood intake area shall be installed for a barbecue 
unit and, when the duct penetrates a ceiling or a 
floor, it shall be enclosed in a fire-resistive shaft 
covered on one side as required for a 1-hour fire- 
resistive construction with no combustible material 
used inside the fire protection. The shaft shall be 
separated from the duct by a minimum one (1) inch 
(25.4 mm) airspace vented to the outside air, and the 
duct shall terminate not less than eighteen (18) 
inches (457 mm) above the roof surface. A minimum 
clearance of twenty-four (24) inches (610 mm) shall 
be maintained between the cooking top and the 
combustible material, and the hood shall be as wide 
as the open-top broiler and be centered over the unit. 



922.0 Pool Heaters. 

922.1 Location. A pool heater shall be located or 
protected so as to minimize accidental contact of hot 
surfaces by persons. [NFPA 54:9.21.1] 

922.2 Clearance. The installation of pool heaters 
shall comply with the following requirements: 

(A) In no case shall the clearances be such as to 
interfere with combustion air, draft hood, or 
vent terminal clearance and relief, and 
accessibility for servicing. 

(B) A listed pool heater shall be installed in accordance 
with its listing and the manufadurer's instructions. 

(C) An unlisted pool heater shall be installed with a 
minimum clearance of twelve (12) inches (300 mm) 
on all sides and the rear. A combustible floor 
under an unlisted pool heater shall be protected 
in an approved manner. [NFPA 54:9.21.2] 

922.3 Temperature or Pressure-Limiting Devices. 

(A) An unlisted pool heater shall be provided with 
overtemperature protection or overtemperature 
and overpressure protection by means of an 
approved device(s). 

(B) Where a pool heater is provided with over- 
temperature protection only and is installed 
with any device in the discharge line of the 
heater that can restrict the flow of water from 
the heater to the pool (such as a check valve, 
shutoff valve, therapeutic pool valving, or flow 
nozzles), a pressure-relief valve shall be installed 
either in the heater or between the heater 
and the restrictive device. [NFPA 54:9.21.3] 

922.4 Bypass Valves. Where an integral bypass 
system is not provided as a part of the pool heater, 
a bypass line and valve shall be installed between 
the inlet and outlet piping for use in adjusting the 
flow of water through the heater. [NFPA 54:9.21.4] 

922.5 Venting. A pool heater listed for outdoor 
installation shall be installed with the venting means 
supplied by the manufacturer and in accordance 
with the manufacturer's instructions. (See Sections 
802.2.5, 802.2.6, 802.3.4, and 802.8.) [NFPA 54:9.21.5] 



921 .0 Outdoor Cooking Appliances. 

921.1 Listed Units. Listed outdoor cooking 
appliances shall be installed in accordance with their 
listing and the manufacturers' instructions. [NFPA 
54:9.20.1] 

921.2 Unlisted Units. Unlisted outdoor cooking 
appliances shall be installed outdoors with clearances 
to combustible material of not less than thirty-six (36) 
inches (910 mm) at the sides and back and not less 
than forty-eight (48) inches (1,220 xmn) at the front. 
In no case shall the appliance be located under 
overhead combustible construction. [NFPA 54:9.20.2] 



923.0 Refrigerators. 

923.1 Clearance. Refrigerators shall be provided 
with clearances for ventilation at the top and back in 
accordance with the manufacturers' instructions. 
Where such instructions are not available, at least 
two (2) inches (50 mm) shall be provided between 
the back of the refrigerator and the wall and at least 
twelve (12) inches (300 mm) above the top. [NFPA 
54:9.22.1] 

923.2 Venting or Ventilating Kits Approved for 
Use With a Refrigerator. Where an accessory kit is 
used for conveying air for burner combustion or tmit 



162 



INSTALLATION OF SPECIFIC EQUIPMENT 



923.2 - 926.3 



cooling to the refrigerator from areas outside the 
room in which it is located, or for conveying 
combustion products diluted with air containing 
waste heat from the refrigerator to areas outside the 
room in which it is located, the kit shall be installed 
in accordance with the refrigerator manufacturer's 
instructions. [NFPA 54:9.22.2] 

924.0 Room Heaters. 

924.1 Prohibited installations. Unless specifically 
permitted by the Authority Having Jurisdiction, 
unvented room heaters shall not be installed as 
primary heat sources. Unvented room heaters shall not 
be pentnitted in spaces that do not have the required 
volume of indoor air as defined in section 902.1B). 

[HCD 1] Unvented fuel-burning room heaters shall not be 
installed, used, maintained, or permitted to exist in a Group 
R Occupancy. 

924.1.1 Unvented room heaters shall not be 
installed in bathrooms or bedrooms. [NFPA 54: 
10.23.1] This subsection shall not apply to 
portable oil fired unvented heating appliances 
used as supplemental heating in Group S, 
Divisions 3, 4, and 5, and Group U Occupancies, 
and regulated by the Fire Code. 

Exceptions: 

(1) Where approved by the Authority Having 
Jurisdiction, one listed wall-mounted 
unvented room heater equipped with an 
oxygen depletion safety shutoff system shall 
be permitted to be installed in a bathroom 
provided that the input rating shall not 
exceed 6,000 Btu/hr. (1760 W/hr) and 
combustion and ventilation air is provided 
as specified in Section 701.2. [NFPA 54:10.23.1] 

(2) Where approved by the Authority Having 
Jurisdiction, one listed wall-mounted 
unvented room heater equipped with an 
oxygen depletion safety shutoff system shall 
be permitted to be installed in a bedroom 
provided that the input rating shall not 
exceed 10,000 Btu/hr. (2930 W/hr.) and 
combustion and ventilation air is provided as 
specified in Section 701.2. [NFPA 54:10.23.1] 

[HCD 1] Unvented fuel-burning room heaters shall 
not be installed, used, maintained, or permitted to exist 
in a Group R Occupancy. 

924.2 installations in Institutions. Room heaters 
shall not be installed in the following occupancies: 
(1) residential board and care; and (2) health care. 
[NFPA 54:9.23.2] 

924.3 Clearance. A room heater shall be placed so as 
not to cause a hazard to walls, floors, curtains, 
furniture, doors when open, and so on, and to the 



free movements of persons within the room. Heaters 
designed and marked, "For use in noncombustible 
fireplace only," shall not be installed elsewhere. 
Listed room heaters shall be installed in accordance 
with their listings and the manufacturers' 
instructions. In no case shall the clearances be such as 
to interfere with combustion air and accessibility. 
Unlisted room heaters shall be installed with 
clearances from combustible material not less than 
the following: 

(A) Circulating Type. Room heaters having an 
outer jacket surrounding the combustion 
chamber, arranged with openings at top and 
bottom so that air circulates between the 
inner and outer jacket, and arranged 
without openings in the outer jacket to 
permit direct radiation, shall have clearance 
at sides and rear of not less than twlve (12) 
inches (300 mm). 

(B) Radiating Type. Room heaters other than 
those of the circulating type described in 
Section 924.3(a) shall have clearance at sides and 
rear of not less than eighteen (18) inches (460 
mm), except that heaters that make use of 
metal, asbestos, or ceran:uc material to direct 
radiation to the front of the heater shall have 
a clearance of thirty-six (36) inches (910 mm) 
in front and, if constructed with a double 
back of metal or ceramic, shall be permitted 
to be installed with a clearance of eighteen 
(18) inches (460 mm) at sides and twelve (12) 
inches (300 nmi) at rear. Combustible floors 
under tinlisted room heaters shall be protected 
in an approved manner. [NFPA 54:9.23.3] 

924.4 Wall-Type Room Heaters. Wall-type room 
heaters shall not be installed in or attached to walls 
of combustible material unless listed for such 
installation. [NFPA 54:9.23.4] 

925.0 Stationary Gas Engines. The installation of 
gas engines shall coriform with NFPA 37, Standard 
for the Installation and Use of Stationary Combustion 
Engines and Gas Ttirbines. [NFPA 54:9.24] 

926.0 Gas-Fired Toilets. 

926.1 Clearance. A listed gas-fired toilet shall be 
installed in accordance with its listing and the 
manufacturer's instructions, provided that the 
clearance shall in any case be stifficient to afford ready 
accessibility for use, cleanout, and necessary servicing. 

926.2 Mounting. Listed gas-fired toilets installed on 
combustible floors shall be listed for such 
installation. 

926.3 Installation. Vents or vent connectors that are 
capable of being contacted during casual use of the 
room in which the toilet is installed shall be protected 
or shielded to prevent such contact. [NFPA 54:9.25] 



163 



927.0 - Figure 9-2 



2007 CALIFORNIA MECHANICAL CODE 



927.0 Unit Heaters. 

927.1 Support. Suspended-type unit heaters shall be 
safely and adequately supported with due consi- 
deration given to their weight and vibration 
characteristics. Hangers and brackets shall be of 
noncombustible material. [NFPA 54:9.26.1] 

927.2 Clearance. 

(A) Suspended-Type Unit Heaters. Suspended-type 
unit heaters shall comply with the following 
requirements: 

(1) A listed unit heater shall be installed with 
clearances from combustible material of not 
less than eighteen (18) inches (460iiun) at the 
sides, twelve (12) inches (300 mm) at the 
bottom, and six (6) inches (150 mm) above 
the top where the unit heater has an internal 
draft hood, or one (1) inch (25mm) above the 
top of the sloping side of a vertical draft 
hood. A unit heater listed for reduced 
clearances shall be installed in accordance 
with its listing and the manufacturer's 
instructions. 

(2) Unlisted unit heaters shall be installed with 
clearances to combustible material of not 
less than eighteen (18) inches (460nrai). 

(3) Clearances for servicing shall be in 
accordance with the manufacturers' 
recommendations contained in the 
installation instructions. 

(B) Fioor-Mounted-Type Unit Heaters. Floor- 
mounted-type unit heaters shall comply with the 
following requirements: 

(1) A listed unit heater shall be installed with 
clearances from combustible material at the 
back and one side only of not less than six (6) 
inches (150 mm). Where the flue gases are 
vented horizontally, the six (6) inches (150 mm) 
clearance shall be measured from the draft 
hoqd or vent instead of the rear wall of the 
unit heater. A unit heater listed for reduced 
clearances shall be installed in accordance 
with its listing and the manufacturers' 
instructions. 

(2) Floor-mounted-type unit heaters installed 
on combustible floors shall be listed for such 
installation. 

(3) Combustible floors under unlisted floor- 
mounted unit heaters shall be protected in an 
approved manner. 

(4) Clearances for servicing shall be in, 
accordance with the manufacturers' 
recommendations contained in the 
installation instructions. [NFPA 54:9.26.2] 

927.3 Combustion and Circulating Air. Combustion 



and circulating air shall be provided in accordance 
with Section 701.0. [NFPA 54:6.26.3] 

927.4 Ductwork. A imit heater shall not be attached 
to a warm-air duct system unless listed and marked 
for such installation. [NFPA 54:6.26.4] 

927.5 Installation in Commercial Garages and 
Aircraft Hangars. Unit heaters installed in garages 
for more than three motor vehicles or in aircraft 
hangars shall be of a listed type and shall be installed 
in accordance with Sections 911.8 and 911.9. [NFPA 
54:9.26.5] 

928.0 Wall Furnaces. 

928.1 Installation. 

(A) Listed wall furnaces shall be installed in 
accordance with their listings and the 
manufacturers' instructions. Wall furnaces 
installed in or attached to combustible 
material shall be listed for such installation. 

(B) Unlisted wall furnaces shall not be installed 
in or attached to combustible material. 

(C) Vented wall furnaces coimected to a T5rpe B- 
W gas vent system listed only for a single 
story shall be installed only in single-story 
buildings or the top story of multistory 
buildings. Vented wall furnaces connected 
to a Type B-W gas vent system listed for 



Installation of B-W gas 
vent for each subsequent 
ceiling or floor level of 
multistory buildings 




Fire stop spacers supplied 
by manufacturer of B-W 
gas vent 



Plate cut away to provide 
passage of B-W gas vent 



Installation of B-W gas 
vent for single-story 
buildings or for first-floor 
of multistory buildings 




Nail fire stop 
spacer securely 



Ceiling plate spacers to center 
B-W gas vent in stud space — 
nail securely at both ends 



Plate out away for full width of 
stud space to provide ventilation 

Header plate of "'/ / T K— Studs on 16 in. (410 mm) 
vented wall furnace / / '^ centers 
(also acts as fire stop) / sheet metal screw 

Use manufacturer's ^^^^ P'^'^ '° ^^^'^^^ 
method of fastening 
pipe to base plate 

FIGURE 9-2 Installation of Type B-W Gas Vents 
for Vented Wall Furnaces. 



164 



INSTALLATION OF SPECIFIC EQUIPMENT 



928.1 -930.5 



installation in multistory buildings shall be 
permitted to be installed in single-story or 
multistory buildings. Type B-W gas vents 
shall be attached directly to a solid header 
plate that serves as a fire stop at that point 
and shall be permitted to be an integral 
part of the vented wall furnace. The stud 
space in which the vented wall furnace is 
installed shall be ventilated at the first 
ceiling level by installation of the ceiling 
plate spacers furnished with the gas vent. 
Fire stop spacers shall be installed at 
each subsequent ceiling or floor level 
penetrated by the vent. (See Figure 9-2 for 
Type B-W gas vent installation.) 

(D) Direct-vent wall furnaces shall be installed 
with the vent-air intake terminal in the 
outside atmosphere. The thickness of the 
walls on which the furnace is mounted shall 
be within the rarige of wall thickness marked 
on the furnace and covered in the 
manufacturer's installation instructions. 

(E) Panels, grilles, and access doors that are 
required to be removed for normal servicing 
operations shall not be attached to the 
building. For additional information on the 
venting of wall furnaces, consult Section 802.0 
in this code. [NFPA 54:9.27.1] 

928.2 Location. Wall furnaces shall be located so as 
not to cause a hazard to walls, floors, curtains, 
furniture, or doors. Wall furnaces installed between 
bathrooms and adjoining rooms shall not circulate 
air from bathrooms to other parts of the building. 
[NFPA 54:9.27.2] 

928.3 Combustion and Circulating Air. 

Combustion and circulating air shall be provided in 
accordance with Section 701.0 [NFPA 54:9.27.3]. 

929.0 Appliances for Installation in Manufactured 
Housing. Appliances installed in manufactured 
housing after the initial sale shall be listed for 
installation in manufactured housing, or approved, 
and shall be installed in accordance with the 
requirements of this code and the manufacturers' 
installation instructions. Appliances installed in the 
living space of manufactured housing shall be in 
accordance with the requirements of Section 701.0. 
[NFPA 54:9.30] 

930.0 Small Ceramic Kilns. 

930.1 General. The provisions of this section apply 
to kilns used for ceramics that have a maximum 
interior volume of twenty (20) cubic feet (0.566 m') 
and are used for hobby or noncommercial purposes. 



930.2 Installation. Kilns shall be installed in 
accordance with the manufacturers' instructions and 
the provisions of this code. 

930.3 Fuel-Gas Controls. Fuel-gas controls shall 
comply with Sections 1312.1.4 and 306.0. Standing 
pilots shall not be used with gas-fired kilns. 

930.4 Electrical Equipment. All electrical equipment 
used as part of, or in connection with, the installation 
of a kiln shall comply with the requirements set forth 
in the Electrical Code. 

930.5 Installations Inside Buildings. In addition to 
other requirements specified in this section, interior 
installation shall meet the following requirements: 

930.5.1 Kiln Clearances. The sides and tops of 
kilns shall be located a minimum of eighteen 
(18) inches (457 nam) from any noncombustible 
wall surface and three (3) feet (914 mm) from 
any combustible wall surface. Kilns shall be 
installed on noncombustible flooring consisting 
of at least two (2) inches (51 mm) of solid 
masonry or concrete extending at least twelve 
(12) inches (305 mm) beyond the base or 
supporting members of the kiln. 

Exception: These clearances may be 
reduced, provided the kiln is installed in 
accordance with its listing. 

In no case shall the clearance on the gas or 
electrical control side of a kiln be reduced to less 
than thirty (30) inches (762 nun). 

930.5.2 Hoods. A canopy-type hood shall be 
installed directly above each kiln. The face 
opening area of the hood shall be equal to or 
greater than the top horizontal surface area of 
the kiln. The hood shall be constructed of not 
less than 0.024 inch (0.61 mm) (No. 24 U.S. 
gauge) galvanized steel or equivalent and be 
supported at a height of between twelve (12) 
inches (305 mm) and thirty (30) inches (76 mm) 
above the kiln by noncombustible supports. 

Exception: Electric kilns installed with listed 
exhaust blowers may be used when marked 
as being suitable for the kiln and installed in 
accordance with manufacturer's instructions. 

930.5.3 Gravity Ventilation Ducts. Each hood 
shall be connected to a gravity ventilation duct 
extending in a vertical direction to outside the 
building. This duct shall be of the same 
construction as the hood and shall have a 
nninimum cross-sectional area of not less than one- 
fifteenth of the face opening area of the hood. The 
duct shall terminate a mirumum of twelve (12) 
inches (305 mm) above any portion of a building 
within four (4) feet (1,219 mm) and terminate no 
less than four (4) feet (1,219 mm) from any 
openable windows or other openings into the 



165 



930.5 - 932.5 



2007 CALIFORNIA MECHANICAL CODE 



building or adjacent property line. The duct 
opening to the outside shall be shielded, without 
reduction of duct area, to prevent entrance of rain 
into the duct. The duct shall be supported at each 
section by noncombustible supports. 

930.5.4 Makeup Air. Provisions shall be made 
for air to enter the room in which a kiln is 
installed at a rate at least equal to the air being 
removed through the kiln hood. 

930.5.5 Hood and Duct Clearances. Every 
hood and duct serving a fuel-btirning kiln shall 
have a clearance from combustible construction 
of at least eighteen (18) inches (457 mm). This 
clearance may be reduced in accordance with 
Table 3-2. 

930.6 Exterior Installations. KUns shall be installed 
with minimum clearances as specified in Section 

930.5.1. Wherever a kiln is located under a roofed 
area and is partially enclosed by more than two 
vertical wall surfaces, a hood and gravity ventilation 
duct shall be installed to comply with Sections 

930.5.2, 930.5.3, and 930.5.5. 

931.0 Attic Furnace (Upright and Horizontal) 

Upright furnaces may be installed in an attic or 
furred space more than five (5) feet (1,524 mm) in 
height, provided the required listings and furnace 
and duct clearances are observed. Horizontal 
furnaces may be installed in an attic or furred space, 
provided the required Ustings and furnace and duct 
clearances are observed. Clearances of a warm-air 
attic furnace from combustibles shall be as specified 
in Section 304.1. 

931.1 An attic or furred space in which a warm-air 
furnace is installed shall be accessible by an opening 
and passageway as large as the largest piece of the 
furnace and in no case less than thirty (30) inches by 
thirty (30) inches (762 mm x 762 mm) continuous 
from the opening to the furnace and its controls. 

Exception: The access opening into the space 
may be twenty-two (22) inches by thirty (30) 
inches (559 nun x 762 mm), provided the largest 
piece of equipment can be removed through the 
opening. 

931 .2 The distance from the passageway access to 
the furnace shall not exceed twenty (20) feet (6,096 
mm) measured along the center line of the 
passageway. The passageway shall be tmobstructed 
and shall have continuous solid flooring not less 
than twenty-four (24) inches (610 nnm) wide from the 
entrance opening to the furnace. 

931 .3 A level working platform not less than thirty 
(30) inches (762 mm) in depth and width shall be 
provided in front of the entire firebox side of the 



warm-air furnace, and if the furnace temperature- 
limit control, air filter, fuel-control valve, vent coUar, 
or air-handling unit is not serviceable from the 
firebox side of the furnace, a continuous floor not less 
than twenty-four (24) inches (610 mm) in width shall 
be provided from the platform in front of the firebox 
side of the furnace to and in front of this equipment. 

Exception: A working platform need not be 
provided when the furnace can be serviced from 
the required access opening. 

931.4 A permanent electric outlet and lighting 
fixture controlled by a switch located at the required 
passageway opening shall be provided at or near the 
furnace. 

932.0 Warm-Air Furnaces Located in Under-Floor 
Spaces. 

[HCD 1, HCD 2 and SFM] warm-air furnaces in under- 
floor spaces shall comply with Sections 932.1 through 

932.5 of this code: 

[For SFIVI] Applications listed in Section 111 regulated 
by the Office of State Fire Marshal shall comply with this 
Section. 

932.1 Clearance from combustibles shall be as specified in 
Section 304.1. 

932.2 An access opening and passageway of a height and 
width sufficient to permit removal of the furnace, but in 
no case less than thirty (30) inches by thirty (30) inches 
(762 mm x 762 mm), shall be provided to the working 
space in front of the furnace. The access opening to the 
passageway shall be through an opening in an exterior 
wall of the building or through a trap door within the 
building. The distance from the passageway access to the 
center line of the working space in front of the furnace 
burner shall not exceed twenty (20) feet (6096 mm) 
measured along the center line of the passageway. 

932.3 A furnace supported from the ground shall rest on 
a concrete slab extending not less than three (3) inches (76 
mm) above the adjoining ground level. 

932.4 The lowest portion of a suspended furnace shall have 
a clearance of at least size (6) inches (152 mm) from the 
ground. Excavation necessary to install a furnace shall 
extend to a depth of six (6) inches (152 mm) below and 
twelve (12) inches (305 mm) on all sides of the furnace, 
except the control side, which shall have thirty (30) inches 
(76 mm). If the depth of the excavation for either furnace or 
passageway exceeds twelve (12) inches (305 mm), walls of 
the excavation shall be lined with concrete or masonry 
extending four (4) inches (102 mm) above the adjoining 
ground level. In floodplain areas the entire crawl space 
grade or height shall provide twelve (12) inch (305 mm) 
clearance between the bottom of the furnace and the ground. 

932.5 A permanent electric outlet and lighting fixture 
controlled by a switch located at the passageway opening 
shall be provided at or near the furnace. 



166 



CHAPTER 10 



STEAM AND HOT WATER BOILERS 



1001.0 Purpose. 

The purpose of this chapter is to establish and 
provide minimum standards for the protection of 
public welfare, health, safety, and property by 
regulating and controlling the quaHty, location, and 
installation of steam and hot water boilers. 

1002.0 Scope. 

The requirements of this chapter shall apply to the 
construction, installation, operation, repair, and 
alteration of all boilers and pressure vessels. 

Exceptions: 

(1) Listed and approved potable water heaters 
with a nominal capacity of 120 gallons (454 L) 
or less having a heat input of 200,000 Btu/h 
(58.62 kW) or less used for hot water supply 
at a pressure of 160 psi (ll03 kPa) or less and 
at temperatures not exceeding 210°F (99°C), 
as regulated by the Plumbing Code. 

(2) Pressure vessels used for unheated water 
supply, including those containing air that 
serves only as a cushion and is compressed 
by the introduction of water and tanks 
connected to sprinkler systems. 

(3) Portable unfired pressure vessels and Interstate 
Commerce Commission (I.C.C.) containers. 

(4) Containers for liquefied petroleum gases, 
bulk oxygen, and medical gas that are 
regulated by the Fire Code. 

(5) Unfired pressure vessels in Groups B, F, H, 
M, R, S, and U Occupancies having a volume 
of five (5) cubic feet (0.14 m') or less and 
operated at pressures not exceeding 250 psi 
(1,724 kPa). 

(6) Pressure vessels used in refrigeration 
systems that are regulated by Chapter 11 of 
this code. 

(7) Pressure tanks used in conjunction with 
coaxial cables, telephone cables, power 
cables, and other similar humidity control 
systems. 

(8) Any boiler or pressure vessel subject to 
regular inspection by federal inspectors or 
licensed by federal authorities. 

(9) Boilers within the scope of NFPA 85, 
including associated fuel systems shall be 
designed and installed in accordance with 
NFPA 85, Boiler and Combustion Systems 
Hazards Code. 



1003.0 Workmanship. 

All equipment, appurtenances, devices, and 
piping shall be installed in a workmanlike manner 
in conformity with the provisions and intent of 
this chapter. 

1004.0 Definitions. 

Certain words and terms used in this chapter, unless 
clearly inconsistent with their context, shall mean as 
follows: 

1004.1 -A- 

AUTOMATIC BOILER - When appUed to any class 
of boiler defined below, such boiler shall be 
equipped with certain controls and limit devices, as 
specified in Section 1011.0 and Table 10-3. 



1004.2 



-B- 



BOILER - A closed vessel used for heating water or 
liquid, or for generating steam or vapor by direct 
application of heat from combustible fuels or 
electricity. 

BURNER, AUTOMATIC BOILER - A device to 
convey fuel into the combustion chamber in proximity 
to its combustion-air supply so as to permit a stable 
controlled heat release compatible with the burner 
design and that is equipped with an ignition system to 
reliably ignite the entire heat release surface of the 
burner assembly. 

1004.3 -C- 

CONTINUOUS PILOT - A pilot that burns without 
turndown throughout the entire period that the 
boiler is in service, whether or not the main burner is 
firing. 

1004.4 -D- 

No definitions. 

1004.5 -E- 

No definitions. 

1004.6 -F- 

No definitions. 

1004.7 -G- 

No definitions. 



167 



1004.8-1005.1 



2007 CALIFORNIA MECHANICAL CODE 



1004.8 



-H- 



HOT WATER-HEATING BOILER - A boUer having 
a volume exceeding 120 gallons (454 L), a heat input 
exceeding 200,000 Btu/h (58.62 kW), or an operating 
temperature exceeding 210°F (99°C) that provides 
hot water to be used externally to itself. 



1004.9 



-I- 



INTERLOCK - A device that senses a limit or off- 
Umit condition or improper sequence of events and 
shuts down the offending or related piece of 
equipment or prevents proceeding in an improper 
sequence in order to prevent a hazardous condition 
from developing. 

INTERMITTENT PILOT - A pilot that bums during 
light-off and while the main burner is firing, and that 
is shut off with the main btimer. 

INTERRUPTED PILOT - A pilot that bums during 
light-off and that is shut off during normal operation 
of the main burner. 



1004.10 

No definitions. 

1004.11 

No definitions. 



-J- 



-K- 



POWER BOILER - A boiler in which steam is gene- 
rated at pressures exceeding fifteen (15) psi (103 kPa). 

POWER HOT WATER BOILER (HIGH TEP.1PERATURE 
WATER BOILER) - A boiler used for heating water 
or liquid to a pressure exceeding 160 psi (1,103 kPa) 
or to a temperature exceeding 250°F (121 °C). 

PRESSURE VESSEL (unfired) - A closed container, 
having a nominal internal diameter exceeding six (6) 
inches (152.4 mm) and a volume exceeding 1-1/2 
cubic feet (42 L), for liquids, gases, vapors subjected 
to pressures exceeding fifteen (15) psi (103 kPa), or 
steam under any pressure. 

PURGE - The acceptable method of scavenging the 
combustion chamber, boiler passes, and breeching to 
remove all combustible gases. 



1004.18 

No definitions. 

1004.17 

No definitions. 



-Q- 



-R- 



1004.18 -S- 

STEAM-HEATING BOILER - A boiler operated at 
pressures not exceeding fifteen (15) psi (103 kPa) for 
steam. 



1004.12 -L- 

LOW-PRESSURE HOT WATER-HEATING BOILER - 

A boiler in which water is heated for the purpose of 
supplying heat at pressures not exceeding 160 psi 
(1,102 kPa) and temperatures not exceeding 250°F 
(121°C). 

1004.13 -M- 

MINIATURE BOILER - A power boiler having an 
internal shell diameter of sixteen (16) inches (406 mm) 
or less, a gross volume of five (5) cubic feet (142 L) or 
less, a heating surface of twenty (20) square feet (1.86 m^) 
or less (not applicable to electric boilers), and not 
exceeding 100 psi (689 kPa). 



1004.14 

No definitions. 



-N- 



-P- 



1004.15 

PACKAGE BOILER - Any class of boiler defined 
herein and shall be a boiler equipped and shipped 
complete with fuel-burning equipment, automatic 
controls and accessories, and mechanical draft 
equipment, if used. 

PILOT - A burner smaller than the main burner that 
is ignited by a spark or other independent and stable 
ignition source, and that provides ignition energy 
required to immediately light off the main burner. 



1004.19 


-T- 


No definitions. 




1004.20 


-U- 


No definitions. 




1004.21 


-V- 


No definitions. 




1004.22 


-w- 


No definitions. 




1004.23 


-X- 


No definitions. 




1004.24 


-Y- 


No definitions. 




1004.25 


-Z- 


No definitions. 





1005.0 Detailed Requirements. 

1005.1 Safety Requirements. The construction of 
boilers and pressure vessels and the installation 
thereof shall conform to minimum requirements for 
safety from structural and mechanical failure and 
excessive pressures, as established by the Authority 
Having Jurisdiction in accordance with nationally 
recognized standards. 



168 



STEAM AND HOT WATER BOILERS 



1005.2-1009.0 



1005.2 Controls. Required electrical, mechanical, safety, 
and operating controls shall carry approval of an 

I approved testing agency or be accepted by the Authority 
Having Jurisdiction. Electrical controls shall be of such 
design and construction as to be suitable for installation 
in the environment ia whidi they are located. 

1 005.3 Gauges. All steam boilers shall be provided 
with a pressure gauge and a water level glass. All 
water boilers shall be provided with a pressure 
gauge and a temperature indicator. 

1005.4 Stack Dampers. Stack dampers on boilers 
fired with oil or solid fuel shall not close off more 
than 80 percent of the stack area when closed, except 
on automatic boilers with prepurge, automatic draft 
control, and interlock. Operative dampers shall not 
be placed within any stack, flue, or vent of a gas- 
fired boiler, except on an automatic boiler with 
prepurge, automatic draft control, and interlock. 

1005.5 Welding. Welding on pressure vessels shall 
j be done by certified welders in conformity with 

nationally recognized standards. 

1006.0 Expansion Tani<s. 

1006.1 General. All hot-water-heating systems shall 
be provided with an air expansion tank securely 
fastened to the structure. Supports shall be adequate 
to carry twice the weight of the tank filled with water 
without placing any strain on connecting piping. 

All hot-water-heating systems incorporating hot 
water tanks or fluid relief columns shall be so 
installed as to prevent freezing under normal 
operating conditions. 

1006.2 Systems with Open Expansion Tanks. 

Systems equipped with an open expansion tank to 
satisfy thermal water expansion shall be provided 
with an indoor overflow from the upper portion of 
the expansion tank in addition to an open vent. The 
indoor overflow shall be carried within the building 
to a suitable plumbing fixture or to the basement. 

1006.3 Closed-Type Systems. Systems of the closed 
type shall have an airtight tank or other suitable air 
cushion that will be consistent with the volume and 
capacity of the system, and shall be suitably 
designed for a hydrostatic test pressure of two and 
one-half (2-1/2) times the allowable working 

^ pressure of the system. Expansion tanks for systems 
' designed to operate at or above 30 psig shall be 
constructed ia accordance with nationally recogruzed 
standards approved by the Authority Having 
Jurisdiction. Provisions shall be made for draining 
the tank without emptying the system, except for 
pressurized tanks. 



1006.4 Minimum Capacity of Closed-Type Tank. 

The minimum capacity of the closed-type expansion 
tank may be determined from Tables 10-1 and 10-2 
or from the following formula: 

Vt = (0.00041t- 0.0466) Vs 



(Pa 
(Pf 



Pa) 
Po) 



WHERE: 

Vt = minimum volume of expansion tank, gallons. 

Vs = volume of system, not including expansion 
tank, gallons. 

t = average operating temperature, °F. 

Pa = atmospheric pressure, feet H2O absolute. 

Pf = fill pressure, feet H2O absolute. 

Po = maximum operating pressure, feet H2O 
absolute. 

1007.0 Safety or Relief Valve Discharge. 

The discharge from relief valves shall be piped to 
within eighteen (18) inches (457 mm) of the floor or 
to an open receptacle, and when the operating 
temperature is in excess of 212°F (100°C), shall be 
equipped with a splash shield or centrifugal 
separator. When the discharge from safety valves 
would result in a hazardous discharge of steam 
inside the boiler room, such discharge shall be 
extended outside the boiler room. No valve of any 
description shall be placed between the safety or 
relief valve and the boiler, nor on the discharge pipe 
between the safety valve and the atmosphere. 
Discharges from relief valves on industrial boilers 
shall be discharged to an approved location. 

1008.0 Shutoff Valves. 

An approved manual shutoff valve shall be installed 
upstream of all control devices on the main burner of 
a gas-fired boiler. The takeoff point for the gas 
supply to the pilot shall be upstream of the gas 
shutoff valve of the main burner and shall be valved 
separately. A union or other approved means of 
disconnect shall be provided immediately down- 
stream of these shutoff valves. 

1009.0 Gas-Pressure Regulators. 

An approved gas-pressure regulator shall be 
installed on gas-fired boilers where the gas supply 
pressure is higher than that at which the main 
burner is designed to operate. A separate approved 
gas-pressure regulator shall be installed to regulate 
the gas pressure to the pilot or pilots. 



169 



1010.0-1015.0 



2007 CALIFORNIA MECHANICAL CODE 



1010.0 Low-Water Cutoff. 

Hot water heating boilers, other than manually fired, 
shall be equipped with a low-water cutoff, except 
that a coil-type boiler or a water-tube boiler that 
requires forced circulation to prevent overheating of 
the coils or tubes shall have a flow-sensing device 
installed in the outlet piping in lieu of the low-water 
cutoff. The required low-water cutoff or flow switch, 
as applicable, shall be mounted so as to prevent 
damage to the boiler and to permit testing of the 
fuel-supply cutoff without draining the heating 
system, except that such boilers used in Group R 
Occupancies of less than six dwelling units and 
Group U Occupancies need not be equipped with the 
low-water cutoff or flow switch. 



1011.0 Combustion Regulators - Safety Valves. 

The following requirements shall be retroactive: 

1011.1 Every hot water-heating boiler, other than 
manually fired, shall be equipped with two tempe- 
rature combustion regulators in series. Every steam- 
heating boiler, other than manually fired, shall be 
equipped with a pressure combustion regulator and 
a low-water cutoff. (See Section 1011.0.) 

101 1.2 Boilers and pressure vessels shall be provided 
with the required number, size, and capacity of 
safety or relief valves to ensure positive relief of 
overpressure in accordance with nationally 
recognized standards, as applicable. Valves so 
employed shall be constructed, sealed, and installed 
in accordance with nationally recognized standards, 
as appUcable. 

1012.0 Automatic Boilers. 

Automatic boilers shall be equipped with controls 
and limit devices as set forth in Table 10-3. 
Automatic boilers shall also be equipped with the 
following gauges, as applicable: oil temperature, oil 
suction pressure, high and low gas pressure, stack 
tenaperature, and windbox pressure. 

Except as otherwise specified, gas-fired boilers 
exceeding 400,000 Btu/h (117 kW) input shall 
conform to nationally recognized standards 
approved by the Authority Having Jurisdiction. 

The Authority Having Jurisdiction shall have the 
authority to approve solid-fuel-fired boilers that can 
nieet the safety requirements for automatic gas- or 
oil-fired boilers. 

1013.0 Clearance for Access. 

When boilers are installed or replaced, clearance 



shall be provided to allow access for inspection, 
maintenance, and repair. Passageways around all 
sides of boilers shall have an unobstructed v/idth of 
not less than eighteen (18) inches (457 mm). 
Clearance for repair and cleaning may be provided 
through a door or access panel into another area, 
provided the opening is of sufficient size. 

Exception: Subject to the approval of the 
Authority Having Jurisdiction, boilers may be 
installed with a side clearance of less than 
eighteen (18) inches (457 mm), provided that the 
lesser clearance does not inhibit inspection, 
maintenance, or repair. 

Power boilers having a steam-generating 
capacity in excess of 5,000 pounds per hour (2,268 
kg/h) or having a heating surface in excess of 1,000 
square feet (93 m^) or input in excess of 5,000,000 
Btu/h (1,465 kW) shall have a minimum clearance of 
seven (7) feet (2,134 mm) from the top of the boiler to 
the ceiling. 

Steam-heating boilers and hot-water-heating 
boilers that exceed one of the following limits — 
5,000,000 Btu/h input (1465 kW); 5,000-pound- 
steam-per-hour (2268 kg/h) capacity; or 1,000- 
square-foot (93 m^) heating surface — and power 
boilers that do not exceed one of the following 
limits— 5,000,000 Btu/h input (1465 kW); 5,000- 
pound steam per hour (2268 kg/h) capacity; or 1,000- 
square-foot (1465 kW) heating surface — and all 
boilers with manholes on top of the boiler, except 
those described in the second and fourth paragraphs, 
shall have a minimum clearance of three (3) feet (914 
nun) from the top of the boiler to the ceiling. 

Package boilers, steam-heating boilers, and hot- 
water-heating boilers with no manhole on top of the 
shell and not exceeding one of the above linuts shall 
have a minimum clearance of two (2) feet (610 rrmi) 
from the ceiling. 

1014.0 Boiler Rooms and Enclosures. 

Boiler rooms and enclosures and access thereto shall 
comply with Section 904.0 of this code and the 
Building Code. 

1015.0 Mounting. 

Equipment shall be set or mounted on a level base 
capable of supporting and distributing the weight 
contained thereon. 

Boilers, tanks, and equipment shall be securely 
anchored to the structure. 

Equipment requiring vibration isolation shall be 
installed as designed by a registered engineer and -. 
approved by the Authority Having Jurisdiction. | 



170 



STEAM AND HOT WATER BOILERS 



1016.0-1024.2 



1016.0 Floors. 

Boilers shall be mounted on floors of noncombustible 
construction unless listed for mounting on 
combustible flooring. 

1017.0 Chimneys or Vents. 

Boilers shall be connected to a chimney or vent, as 
provided for other fuel-burning equipment in 
Chapter 8 of this code. 

1018.0 Drainage. 

For heating or hot-water-supply boiler applications, 
the boiler room shall be equipped with a floor drain 
or other means suitable for disposing of the 
accumulation of liquid wastes incident to cleaning, 
recharging, and routine maintenance. No steam pipe 
shall be directly connected to any part of a plumbing 
or drainage system, nor shall any water having a 
temperature above 140°F (60°C) be discharged under 
pressure directly into any part of a drainage system. 
Pipes from broilers shall discharge by means of 
indirect waste piping, as determined by the 
Authority Having Jurisdiction or the boiler 
manufacturer's recommendations. 



Having Jurisdiction that the installation is ready for 
inspection and test. It also shall be the duty of the 
owner or his authorized representative to post in a 
conspicuous position on the installation a notice in 
substantially the following form: "Warning! This 
installation has not been inspected and approved by 
the Authority Having Jurisdiction and shall not be 
covered or concealed until so inspected and 
approved," and it shall be unlawful for anyone other 
than the Authority Having Jurisdiction to remove 
such notice. The Authority Having Jurisdiction shall 
require such tests as it deems necessary to determine 
that the installation complies with the provision of 
this section. Such tests shall be made by the owner or 
his authorized representative in the presence of the 
Authority Having Jurisdiction. 

Exception: On installations designed and 
supervised by a registered professional engineer, 
the Authority Having Jurisdiction shall have the 
authority to permit inspection and testing by 
such engineer. 

When the owner or his authorized 
representative requests inspection of a boiler 
prior to its installation; the Authority Having 
Jurisdiction shall make such inspection. 



1019.0 Fuel Piping, Tanks, and Valves. 

Tanks, piping, and valves for oil-burning appliances 
shall be installed in accordance with NFPA 31, 
Standard for the Ir\staUation of OU-Buming Equipment. 
That portion of the oil-burning system supplied on 
boilers and covered within the scope of NFPA 85 shall 
be installed in accordance with NFPA 85. 

1020.0 Air for Combustion and Ventilation. 

Air for combustion and ventilation shall be provided 
in accordance with Chapter 7 of this code. 

1021.0 Operating Adjustments and Instructions. 

Hot water boiler installations, upon completion, shall 
have controls set, adjusted, and tested by the 
installing contractor. A complete control diagram of 
a permanent legible type, together with complete 
boiler operating instructions, shall be furnished by 
the installer for each installation. 

1022.0 Inspections and Tests. 

An installation for which a permit is required shall 
not be put into service tintil it has been inspected and 
approved by the Authority Having Jurisdiction. 

It shall be the duty of the owner or his 
authorized representative to notify the Authority 



1023.0 Operating Permit. 

It shall be imlawful to operate a boiler or pressure 
vessel without first obtaining a valid operating 
permit to do so from the Authority Having 
Jurisdiction. Such permit shall be displayed in a ■ 
conspicuous place adjacent to the boiler or vessel. 
The operating permit shall not be issued until the 
equipment has been inspected and approved by the 
Authority Having Jurisdiction. 

Exception: The operation only of steam-heating 
boilers, low-pressure hot-water-heating boilers, 
hot water supply boilers, and pressure vessels in 
Group R Occupancies of less than six dwelling 
units and in Group U Occupancies. 

1024.0 Maintenance Inspection. 

The Authority Having Jurisdiction shall inspect all 
boilers and pressure vessels operated under permit 
at such intervals as deemed necessary, but not less 
frequently than noted below: 

1024.1 Power boilers and miniature boilers shall be 
inspected externally annually. Where construction 
and operating conditions permit, they shall, in 
addition, be subject to inspection internally annually. 

1024.2 Steam-heating boilers and hot-water- 
heating boilers shall be inspected externally 



171 



1024.2 -Table 10-2 



2007 CALIFORNIA MECHANICAL CODE 



annually. Where construction and operating 
conditions permit, they shall, in addition, be subject 
to inspection intemaily atmually. 

1 024.3 Automatic steam-heating boilers shall be 
inspected externally biennially. Where construction 
and operating conditions permit, they shall, in 
addition, be subject to inspection internally 
biermially. 

1 024.4 Unfired pressure vessels shall be inspected 
externally biermially. When subject to corrosion and 
construction permits, they shall, in addition, be 
subject to inspection internally biennially. 

Inspection of boilers and pressure vessels 
covered by insurance may be made by employees 
of the insuring company holding commissions 
from the National Board of Boiler and Pressure 
Vessel Inspectors, subject to approval of the 
Authority Having Jurisdiction. Approved 
insuring company inspectors shall make reports 
on prescribed forms on inspections authorized by 
the Authority Having Jurisdiction. The reports 
shall be filed in the Authority Having Jurisdiction 
office. Company inspectors shall notify the 
Authority Having Jurisdiction of suspension of 
insurance because of dangerous conditions, new 
insurance in effect, and discontinuance of 
insurance coverage. 

1025.0 Operation and Maintenance of Boilers and 
Pressure Vessels. 

Boilers and pressure vessels shall be operated and 
nfiaintained in conformity with requirements for 
adequate protection of the public established by the 
Authority Having Jurisdiction in accordance with 
nationally recognized standards. 

The Authority Having Jurisdiction shall notify 
the owner or authorized representative of defects or 
deficiencies that shall be promptly and properly 
corrected. If such corrections are not made, or if the 
operation of the boUer or pressure vessel is deemed 
unsafe by the Authority Having Jurisdiction, they 
shall have the authority to revoke the permit to 
operate the boiler or pressure vessel. If the operation 
of a boiler or pressure vessel is deemed by the 
Authority Having Jurisdiction to constitute an 
immediate danger, the pressure on such boiler or 
presstire vessel may be relieved at the owner's cost 
and the boiler or pressure vessel shall not thereafter 
be operated without approval of the Authority 
Having Jurisdiction. 



TABLE 10-1 

Expansion Tank Capacities for Gravity 

i4ot Water Systems 

Based on a two-pipe system with an average operating 
water temperature of 170°F (77°C), using cast-iron 
column radiation with a heat emission rate of 150 Btu 
per hotir per square foot (473 W/m^) equivalent direct 
radiation. 



Square Feet of Installed 




Expansion Direct Radiation' 


Tanl< Capacity, Gallons 


(X 0.0929 for m=) 


(X 3.785 for L) 


Up to 350 


18 


Up to 450 


21 


Up to 650 


24 


Up to 900 


30 


Up to 1,100 


35 


Up to 1,400 


40 


Up to 1,600 


2 to 30 


Up to 1,800 


2 to 30 


Up to 2,000 


2 to 35 


Up to 2,400 


2 to 40 



Note: 

' For systems with more than 2,400 square feet (223 
m^) of installed equivalent direct water radiation, the 
required capacity of the cushion tank shall be 
increased on the basis of 1 gallon (3.785 L) tank 
capacity per 33 square feet (3.07 m^) of additional 
equivalent direct radiation. 



TABLE 10-2 


Expansion Tank Capacities for Forced 


Hot Water Systems 


Based on an average operating 


water temperature of 


195°F (90.6°C), a fiU pressure of 12 psig (82.7 kPa), and 


a maximum operating pressure 


of 30 psig (206.8 kPa). 


System Volume,' 


Tank Capacity, 


Gallons 


Gallons 


(X 3.785 for L) 


(X 3.785 for L) 


100 


15 


200 


30 


300 


45 


400 


60 


500 


75 


1,000 


150 


2,000 


300 



' Includes volume of water in boiler, radiation, and 
piping, not including expansion tank. 



172 



CO 

















TABLE 10-3 


























Controls and Limit Devices for Automatic Boilers 
























Safety Control Timing 


1 










Hot 
















(Nominal Maximum Time In Seconds) 










Water 
Tempera- 


Steam 




Control 




Trial for Main 














Burner Flame 












ture and 


Pressure 




and 






Fuel Inppt 










Main 


Assured 


Assured 






Low 


and Low 




Limit 






Range 


Type 


Trial 


Direct ■ 




Burner 


Fuel 


Air 


Low Fire 


Pre- 


Water 


Water 


Approvec 


Device 


Boiler 




(Inclusive), 


°'. 


for 


Electric 


Flame 


Flame 


Supply^ 


Supply^ 


Startup 


purging 


Limit 


Limit 


^"^ ,. 


Systeni 


Group 


Fuel 


Btu/h 


Pilot 


Pilot 


Ignition 


Pilot 


Failure 


Control 


Control 


Control 


Control 


Controls 


Controls 


Stiutoff 


Design 












Not 






Not 




Not 


Not 






Not 




A 


Gas 


0-400,000 


Any type 


90 


Required 


90 


90 


required 


Required 


required 


required 


Required 


Required 


required 


Required 






400,001- 


Interrupted 










Not 




Not 


Not 






Not 




B 


Gas 


2,500,000 


or 
intermittent 


15 


15 


15 


2-4 


required 


Required 


required 


required 


Required 


Required 


required 


Required 






2,500,001- 


Interrupted 


























C 


Gas 


5,000,000 


or 
intermittent 


15 


15 


15 


2-4 


Required 


Required 


Required 


Required 


Required 


Required 


Required 


Required 






Over 




























•D 


Gas 


5,000,000 


Interrupted 


15 


15 


15 


2-4 


Required 


Required 


Required 


Required 


Required 


Required 


Required 


Required 










Not 








Not 




Not 


Not 






Not 




E 


Oil 


0-400,000 


Any type 


Required 


90 


90 


90 


required 


Required 


required 


required 


Required 


Required 


required 


Required 






400,001- 




Not 












Not 


Not 






Not 




F 


Oil 


1,000,000 


Interrupted 


Required 


30 


30 


2-4 


Required 


Required 


required 


required 


Required 


Required 


required 


Required 






1,000,001 




Not 












Not 


Not 






Not 




G 


Oil 


3,000,000. 


Interrupted 


Required 


15 


15 


2-4 


Required 


Required 


required 


required 


Required 


Required 


required 


Required 






Over 




























H 


Oil 


3,000,000 


Interrupted 


15 


15 


60 


2-4 


Required 


Required 


Required 


Required 


Required 


Required - 


Required 


Required 








Not 


Not 


Not 


Not 


Not 


Not 


Not 


Not 


Not 






Not 




K 


Electric 


All 


required 


required 


required 


required 


required 


required 


required 


required 


required 


Required 


Required 


required 


Required 


L 


Gas, Oil 


12,500,000 


Any 


10 sec 


Per 


Per 


Per 


Per 


Per 


Per 


Per 


Per 


Per 


Per 


Per 




and/or 


or more 




per NFPA 


NFPA 


NFPA 


NFPA 


NFPA 


NFPA 


NFPA 


NFPA 


ASME 


ASME 


NFPA 


NFPA 




Coal 






85 


85 


85 


85 


85 


85 


85 


85 


Power 
Boiler 
Code, 

Section 1 
and 

NFPA 85 


Power 
Boiler 
Code 

Section 1 
and 

NFPA 85 


85 


85 


M 


Heat 


Any 


None 


Per 


Per 


Per 


Per 


Per 


Per 


Per 


Per 


Per 


Per 


Per 


Per 




Recover] 






NFPA 


NFPA 


NFPA 


NFPA 


NFPA 


NFPA 


NFPA 


NFPA 


ASME 


ASME 


NFPA 


NFPA 




Steam 






85 


85 


85 


85 


85 


85 


85 


85 


Boiler & 


Boiler & 


85 


85 




Generate 


• 




















Pressure 
Code& 
NFPA 85 


Pressure 
Code& 
NFPA 85 







CO 

H 

m 
> 



D 

I 
O 

H 



m 

33 
CD 

o 

I— 
m 
3J 
CO 



H 

01 

a> 
o 

I 

CO 



Table 10-3 (continued) 2007 CALIFORNIA MECHANICAL CODE 

FOOTNOTES FOR TABLE 1 0-3 (Continued) 

' Fuel input shall be determined by one of the following: 

(a) The maximum burner input as shown on the burner nameplate or as othen/vise identified by the manufacturer. 

(b) The nominal boiler rating, as determined by the building official, plus twenty-five percent (25%). 

^Automatic boilers shall have one flame failure device on each burner, which shall prove the presence of a suitable ignition source 
at the point where it will reliably ignite the main burner, except that boiler groups A, B, E, F, and G, which are equipped with direct 
electric ignition, shall monitor the main burner, and all boiler groups using interrupted pilots shall monitor only the main burner after 
the prescribed limited trial and ignition periods. Boiler group A, equipped with continuous pilot, shall accomplish 100 percent shutoff 
within ninety (90) seconds upon pilot flame failure. The use of intermittent pilots in boiler group C is limited to approved burner units. 

^ In boiler groups B, C, and D a 90-second main burner flame failure limit may apply if continuous pilots are provided on 
manufacturer assembled boiler-burner units that have been approved by an approved testing agency as complying with nationally 
recognized standards approved by the building official. Boiler groups F and G equipped to re-energize their Ignition systems within 
0.8 second after main burner flame failure will be permitted thirty (30) seconds for group F or fifteen (15) seconds for group G to re- 
establish their main burner flames. 

" Boiler groups C and D shall have controls Interlocked to accomplish a nonrecycllng fuel shutoff upon high or low gas pressure, and 
boiler groups F, G, and H using steam or air for fuel atomization shall have controls interlocked to accomplish a nonrecycllng fuel 
shutoff upon low atomizing steam or air pressure. Boiler groups F, G, and H equipped with a preheated oil system shall have 
controls interlocked to provide fuel shutoff upon low oil temperature. 

= Automatic boilers shall have controls interlocked to shut off the fuel supply in the event of draft failure if forced or induced draft 
fans are used or, in the event of low combustion airflow, if a gas power burner is used. Where a single motor directly driving both 
the fan and the oil pump is used, a separate control Is not required. 

° Boiler groups C, D, and H, when firing in excess of 400,000 Btu per combustion chamber, shall be provided with low fire start of Its 
main burner system to permit smooth light-off. This will normally be a rate of approximately one-third of its maximum firing rate. 

' Boiler groups C, D, and H shall not permit pilot or main burner trial for ignition operation before a purging operation of sufficient 
duration to permit a minimum of four complete air changes through the furnace, including combustion chamber and the boiler 
passes. Where this is not readily determinable, five complete air changes of the furnace, including combustion chamber up to the 
first pass, will be considered equivalent. An atmospheric gas burner with no mechanical means of creating air movement or an oil 
burner that obtains two-thirds or more of the air required for combustion without mechanical means of creating air movement shall 
not require purge by means of four air changes, so long as Its secondary air openings are not provided with means of closing. If 
such burners have means of closing secondary air openings, a time delay must be provided that puts these closures In a normally 
open position for four minutes before an attempt for ignition. An installation with a trapped combustion chamber shall, in every case, 
be provided with a mechanical means of creating air movement for purging. 

= Every automatic hot-water-heating boiler, low-pressure hot-water-heating boiler, and power hot water boiler shall be equipped with 
two high-temperature limit controls with a manual reset on the control, with the higher setting interlocked to shut off the main fuel 
supply, except that manual reset on the high-temperature limit control shall not be required on any automatic package boiler not 
exceeding 400,000 Btu/h input and that has been approved by an approved testing agency. Every automatic hot-water heating, 
power boiler, and package hot-water supply boiler shall be equipped with one low-water level limit control with a manual reset 
interlocked to shut off the fuel supply, so installed as to prevent damage to the boiler and to permit testing of the control without 
draining the heating system, except on boilers used in Group R Occupancies of less than six units and in Group U Occupancies 
and further, except that the low-water level limit control is not required on package hot-water supply boilers approved by a nationally 
recognized testing agency. However, a low-water flow limit control installed in the circulating water line may be used Instead of the 
low-water level limit control for the same purpose on coil-type boilers. 

^ Every automatic low-pressure steam-heating boiler, small power boiler, and power steam boiler shall be equipped with two high- 
steam pressure limit controls interlocked to shut off the fuel supply to the main burner with manual reset on the control, with the 
higher setting and two low-water-level limit controls, one of which shall be provided with a manual reset device and independent of 
the feed water controller. Coil-type flash steam boilers may use two high-temperature limit controls, one of which shall be manually 
reset in the hot water coil section of the boiler Instead of the low-water level limit control. 

" Boiler groups 0, D, and H shall use an approved automatic reset safety shutoff valve for the main burner fuel shutoff, which shall 
be interlocked to the programming control devices required. On oil burners where the safety shutoff valve will be subjected to 
pressures in excess of ten (10) psi when the burner is not firing, a second safety shutoff valve shall be provided in series with the 
first. Boiler groups C and D using gas in excess of one (1 ) pound-per-square-inch pressure or having a trapped combustion 
chamber or employing horizontal fire tubes shall be equipped with two approved safety shutoff valves, one of which shall be an 
automatic reset type, one of which may be used as an operating control, and both of which shall be interlocked to the limit-control 
devices required. Boiler groups and D using gas in excess of one (1) pound per square inch pressure shall be provided with a 
permanent and ready means for making periodic tightness checks of the main fuel safety shutoff valves. 

" Control and limit device systems shall be grounded with operating voltage not to exceed 150 volts, except that, upon approval by 
the building official, existing control equipment to be reused in an altered boiler control system may use 220 volt single phase with 
one side grounded, provided such voltage is used for all controls. Control and limit devices shall interrupt the ungrounded side of 
the circuit. A readily accessible means of manually disconnecting the control circuit shall be provided with controls so arranged that 
when they are de-energized, the burner shall be inoperative. 



174 



CHAPTER 11 

REFRIGERATION 



1101.0 Scope. 

Part I of this chapter covers refrigeration systems. 
Refrigeratioii systems, equipment, and devices, 
including the replacement of parts, alterations, and 
substitution of a different refrigerant, shall conform 
to the requirements of this chapter and other 
applicable provisions of this code. 

Occupied spaces within refrigerated areas shall 
comply with this chapter and the applicable 
portions of the Building Code. 

Part II covers cooling towers. 

Part I - Refrigeration Systems 

1102.0 Refrigerants. 

The refrigerant used shall be of a type listed in Table 
11-1 or as classified under Section 1103.0 as 
approved. 

Exception: Lithium bromide absorption systems 
using water as the refrigerant. 

1103.0 Refrigerant Classification. 

Refrigerants shall be classified in accordance with 
the referenced standard for refrigerant designation 
and safety classification in Chapter 17. 

1104.0 Classification of Refrigeration Systems. 

Refrigeration systems shall be classified according to 
the degree of probabiHty that a leakage of refrigerant 
could enter a normally occupied area. 

1104.1 High-Probability System. Systems in which 
the basic design, or the location of components, is 
such that a leakage of refrigerant from a failed 
connection, seal, or component could enter the 
occupied space described in Section 1105.2. 

1104.2 Low-Probability System. Systems that 
cannot be considered as high-probability system are 
classified as low-probability systems. This class 
includes systems whose joints and connections in the 
refrigerant circuit are effectively isolated from the 
occupied space described in Section 1105.2. 

1105.0 Requirements for Refrigerant and Refrige- 
ration System Use. 

1105.1 System Selection. Refrigeration systems 
shall be limited in application in accordance with 
Table 11-2 and the requirements of this section. 



1105.2 Volume of Occupied Space. The quantity of 
refrigerant in a single, independent circuit of a high- 
probability system shall not exceed the amounts 
shown in Table 11-1 based on the volume of the 
occupied space. The volumie of the smallest, enclosed, 
occupied space shall be used to determine the 
permissible quantity of refrigerant in a system that is 
located in, serves, or passes through such space. 

Exceptions: 

(1) If the airflow to any enclosed space served 
by a portion of an air-duct system cannot be 
shut off or reduced below one-quarter of its 

., maximum, the cubical contents of the entire 
space served by that portion of the air-duct 
system shall be used to determine the 
permissible quantity of refrigerant in the 
system. 

(2) Refrigerated process or storage areas 
meeting the requirements of Section 1105.3. 

1105.3 Refrigerated Process and Storage Areas. 

Refrigerant quantities in evaporators and piping 
within rooms or spaces used exclusively for 
processing or storage of materials under refrigerated 
conditions shall not be limited, provided that exiting 
is provided per the Building Code and that: 

1105.3.1 The refrigerated room or space is 
equipped with a refrigerant vapor detection and 
alarm system compljdng with Section 1121.0. 

1105.3.2 The refrigerated room or space is 
sealed from all other portions of the building by 
vapor-tight construction and tight-fitting, 
gasketed doors. 

Exception: Adjoining refrigerated rooms. 

1105.4 Refrigerant Purity. New and reclaimed 
refrigerants are allowed to be used in refrigeration 
systems in accordance with this section. When 
requested, the installer shall furnish a declaration 
identifying the refrigerant by standard "R" desig- 
nation and stating that it meets the requirements of 
Section 1105.4.1 or 1105.4.2. 

Exception: The refrigerant used shall meet the 
purity specifications set by the manufacturer of 
the equipment in which it is used when that 
specification is different from Section 1105.4.1 or 
1105.4.2. 

1105.4.1 New and Reclaimed Refrigerants. 

New and reclaimed refrigerants shall meet the 



175 



1105.4-1106.7 



2007 CALIFORNIA MECHANICAL CODE 



referenced standard for refrigerant specifications 
in Chapter 17. 

1105.4.2 Recovered Refrigerants. Reuse of 
recovered refrigerant that shows no sign of 
contamination is allowed, provided that it has 
been filtered and dried with a listed or approved 
recovery machine, in equipment belonging to 
the same owner as the equipment from which it 
was removed. Recovered refrigerants shall not 
be used in a different owner's equipment tinless 
the refrigerant has been analyzed and found to 
meet the purity requirements of Section 1105.4.1. 

1106.0 General Requirements. 

1106.1 Human Comfort. Cooling systems used for 
human comfort shaU comply with the rettirn-air and 
outside-air provisions for furnaces in Sections 904.7 
and 904.8 of this code. Cooling equipment used for 
human comfort in dwelling vinits shall be sized to 
satisfy the calculated loads determined in accordance 
with the reference standards in Chapter 17 or other 
approved methods. 

1106.2 Supports and Anchorage. Supports and 
anchorage for refrigeration equipment and piping 
shall be designed in accordance with the Building 
Code as Occupancy Category H hazardous facilities. 
Supports shall be noncombustible. 

Exceptions: 

(1) Equipment containing Group Al refrigerants 
may be supported by the same materials 
permitted for the building type. 

(2) The use of approved vibration isolators 
specifically designed for the normal, wind, 
and seismic loads to which they may be 
subject shall be permitted. 

A compressor or portion of a condensing 
imit supported from the ground shall rest on a 
concrete or other approved base extending not 
less than three (3) inches (76 mm) above the 
adjoining ground level. 

1 1 06.3 Access. An xmobstructed readily accessible 
operung and passageway not less than thirty-six (36) 
inches (914 mm) in width and six (6) feet (1829 mm) 
eight (8) inches (203 mm) in height shall be provided 
and maintained to the compressor, valves required 
by this chapter, or other portions of the system 
requiring routine maintenance. 

Exceptions: 

(1) Refrigerant evaporators, suspended over- 
head, may use portable means of access. 

(2) Air filters, brine control or stop valves, fan 



motors or drives, and remotely de-energized 
electrical connections may be provided 
access by an unobstructed space not less 
than thirty (30) inches (762 mm) in depth, 
width, and height. When an access opening 
is immediately adjacent to these items and 
the equipment can be serviced, repaired, 
and replaced from this opening, the dimen- 
sions may be reduced to twenty-two (22) 
inches (559 mm) by thirty (30) inches (762 mm) 
provided the largest piece of equipment can 
be removed through the opening. 

(3) Cooling equipment, using Group Al 
refrigerants or brine, located in an attic or 
furred space may be provided an access 
by a minimum opening and passageway 
thereto of not less than twenty-two (22) 
inches x thirty (30) inches 

(4) Cooling or refrigeration equipment, using 
Group Al or Bl refrigerants or brine, 
located on a roof or on an exterior wall of a 
building, may be provided access as for 
furnaces in Section 904.10 of this code. 

1106.4 Illumination and Service Receptacles. In 

addition to the requirements of Section 309.0, 
permanent lighting fixtures shall be installed for all 
equipment required by this code to be accessible or 
readily accessible. Such fixtures shall provide sufficient 
illumination to safely perform the required tasks for 
which access is provided. Control of the illumination 
source shall be provided at the access entrance. 

Exceptions: 

(1) Lighting fixtures may be omitted when the 
fixed lighting of the building will provide 
the required illumination. 

(2) Equipment located on the roof or on the 
exterior walls of a building. 

1106.5 Protection from IVIechanical Damage. 

Refrigeration systems and portions thereof shall not 
be located in an elevator shaft, diimbwaiter shaft, or a 
shaft having moving objects therein, nor in a location 
where they will be subject to mecharucal damage. 

1 1 06.6 Electrical. Electrically energized components 
of refrigeration systems shall conform to the 
Electrical Code. 

1106.7 Ventilation of Rooms Containing Conden- 
sing Units. Rooms or spaces other than a 
refrigeration machinery room complying with the 
requirements of this chapter in which any 
refrigerant-containing portion of a condensing unit is 
located shall be provided with one of the following 
means of ventilation: 



176 



REFRIGERATION 



1106.7-1107.2 



1106.7.1 Permanent gravity ventilation 
openings of not less than two (2) square feet 
(0.19 m^) net free area opening directly to the 
outside of the building or extending to the 
outside of the building by continuous ducts. 

1 106.7.2 A mechanical exhaust system arranged 
to provide a complete change of air in such room 
or space at least every 20 minutes and to 
discharge to the outside of the building. 

Exceptions: 

(1) A condensing imit in a room or space if 
the cubical content exceeds 1,000 cubic 
feet per horsepower (38.50 m'/kW) of 
the unit. 

(2) A condensing unit in a room or space 
that has permanent gravity ventilation 
having an area of two (2) square feet 
(0.19 m^) or more to other rooms or 
openings exceeding 1,000 cubic feet per 
horsepower (38.50 mVkW). 

1106.8 Prohibited Locations. Refrigeration systems 
or portions thereof shall not be located within a 
required exit enclosure. Refrigeration compressors 
exceeding five (5) horsepower (3.68 kW) rating shall 
be located at least ten (10) feet (3,048 mm) from an 
exit opening in a Group A; Group B; Group E; Group 
F; Group I; Group R, Division 1; or Group S 
Occupancy, unless separated by a one-hour fire- 
resistive occupancy separation. 

1106.9 Condensation Control. Piping and fittings 
that convey brine, refrigerant, or coolants that 
during normal operation could reach a surface 
temperature below the dew point of the 
surrounding air and that are located in spaces or 
areas where condensation could cause a hazard to 
the building occupants or damage to the structure or 
electrical or other equipment shall be protected to 
prevent such an occurrence. 

1106.10 Condensate. Condensate from air- 
cooling coils shall be collected and drained to an 
approved location. Drain pans and coils shall be 
arranged to allow thorough drainage and access 
for cleaning. Where temperatures can drop below 
freezing, heat tracing and insulation of condensate 
drains shall be installed. . 

1 1 06.1 1 Defrost. When defrost cycles are required 
for portions of the system, provisions shall be made 
for collection and disposal of the defrost liquid in a 
safe and sanitary manner. 

1106.12 Overflows. Where condensate or defrost 
liquids are generated in an attic or furred space and 
structural damage may result from overflow, 
provisions for overflow shall be provided. 



1106.13 Condensate, Defrost, and Overflow 
Disposal. Disposal of condensate, defrost, or 
overflow discharges shall comply with Section 310.0. 

1107.0 Refrigeration Machinery Rooms. 

1107.1 When Required. Refrigeration systems shall 
be provided with a refrigeration machinery room 
when any of the following conditions exist: 

1107.1.1 The quantity of refrigerant in a single, 
independent refrigerant circuit of a system 
exceeds Table 11-1 amoxints. 

1107.1.2 Direct- and indirect-fired absorption 
equipment is used. 

Exceptions: Direct and indirect-fired lithium 
bromide absorption systems using water as 
the refrigerant. 

1107.1.3 An Al system having an aggregate 
combined compressor horsepower of 100 (73.55 
kW) or more is used. 

1107.1.4 The system contains other than a Group 
Al refrigerant. 

Exceptions: 

(1) Lithium bromide absorption systems 
using water as the refrigerant. 

(2) Ammonia-water absorption unit 
systems installed outdoors, provided 
that the quantity of refrigerant in a 
single system does not exceed Table 11-1 
amounts and the discharge is shielded 
and dispersed. 

(3) Systems containing less than 300 
pounds (136 kg) of refrigerant R-123 
and located in an approved exterior 
location. 

(4) Systems containing less than 35 pounds 
(16 kg) of refrigerant R-717 and located 
in an approved exterior location. 

Refrigeration machinery rooms shall house 
all refrigerant-containing portions of the system 
other than the piping and evaporators permitted 
by Section 1105.3, discharge piping required of 
this chapter, and cooling towers regulated by 
Part II of this chapter, and their essential piping. 

1107.2 Dimensions. Refrigeration machinery rooms 
shall be of such dimensions that all system parts are 
readily accessible with adequate space for mainte- 
nance and operations. An unobstructed walking 
space at least three (3) feet (914 mm) in width and six 
(6) feet eight (8) inches (2,032 mm) in height shall be 
maintained throughout, allowing free access to at 
least two sides of all moving machinery and 



177 



1107.2-1108.4 



2007 CALIFORNIA MECHANICAL CODE 



approaching each stop valve. Access to refrigeration 
machinery rooms shall be restricted to authorized 
personnel and posted with a permanent sign. 

1107.3 Exits. Exits shall comply with the Building 
Code for special hazards. 

1107.4 Refrigerant-Vapor Aiarms. Machinery 
rooms shall have approved refrigerant-vapor 
detectors located in an area where refrigerant from a 
leak is likely to concentrate and that will activate 
visual and audible alarms. Alarms shall be activated 
at a value not greater than one-half the immediately 
dangerous to life or health (IDLH), or measurement 
consistent therewith; the PEL, or measurement 
consistent therewith; or 25 percent of the LFL, 
whichever is less. 

1107.5 Separation. Refrigeration machinery rooms 
shall be separated from other portions of the 
building, as required in the special hazards 
provisions of the Building Code. Penetrations shall 
be sealed to inhibit the passage of refrigerant vapor. 

1107.6 Combustion Air and Return Air. Combustion 
air or return air shall not be taken from or through a 
refrigeration machinery room. 

Exceptions: 

(1) Refrigeration machinery rooms used 
exclusively for direct-fired absorption 
equipment. 

(2) Direct-vented combustion equipment. 

1107.7 Special Requirements. Open flames or 
devices having an exposed surface exceeding 800°F 
(427°C) are prohibited in refrigeration machinery 



rooms. 



Exceptions: 

(1) Momentary temperature excursions such as 
electrical contacts in Al and Bl systems. 

(2) Refrigeration machinery rooms used 
exclusively for direct-fired absorption 
equipment. 

1108.0 Refrigeration lUlacliinery Room Ventilation. 

1108.1 General. Refrigeration machinery rooms shaU 
be provided with a continuous soxirce of outside air 
for ventilation and removal of rejected heat. 

1108.2 Refrigeration MacPiinery Rooms. Refrigera- 
tion machinery rooms shall be provided with 
dedicated mechanical exhaust systems. The exhaust 
systems shall have the capacity to achieve each of the 
following: 

1 1 08.2.1 Continuously maintain the refrigeration 
machinery room at 0.05 inch (12.44 Pa) water 



gauge negative relative to adjacent spaces 
calculated by: 



Q = 2610Ag%^ 



(Equation 11-1) 



Exception: Refrigeration machinery rooms 
located in entirely detached structures and 
more than twenty (20) feet (6,096 mm) from 
property lines or openings into buildings. 

1 1 08.2.2 Continuously provide 0.5 cubic foot 
per minute of airflow per gross square foot (2.54 
L/s/m^) of floor area within the refrigeration 
machinery rooms as calculated by: 



Q = 0.5Agf 



(Equation 11-2) 



1108.2.3 Limit the temperature rise within the 
refrigeration machinery room to a maximum of 
104°F (40°C) as calculated by: 



Q = E<7/1.08AT 



(Equation 11-3) 



1108.2.4 Provide emergency purge of escaping 
refrigerant as calculated by: 



Q = lOOVc^ 



(Equation 11-4) 



WHERE: 

q = Btu / h of all heat-producing equipment. 

Q = air-flow rate, cubic feet per minute (c£m). 

Ap = pressure difference, inches water gauge. 

Ag = equivalent leakage area, square feet (see the 
Building Code). 

Agf = gross floor area, square feet. 

AT = temperature difference between machinery 
room and supply air (°F). 

G = refrigerant mass in largest system, lbs. 

1108.3 Distribution of Ventilation. Exhaust inlets or 
permanent openings shall be located to provide 
ventilation throughout the entire refrigeration 
machinery room. 

1108.4 Intermittent Control of the Ventilation 
Systems. Fans providing refrigeration machinery 
room temperature control or automatic response to 
refrigerant gas in order to maintain concentrations 
below the PEL may be automatically controlled to 
provide intermittent ventilation as conditions require. 



178 



REFRIGERATION 



1108.5-1109.4 



( \ 



1108.5 Emergency Control of the Ventilation 
Systems. Fans providing emergency purge venti- 
lation for refrigerant escape shall have a clearly 
identified switch of the break-glass type providing 
"on"only control immediately adjacent to and 
outside of each refrigerant machinery room exit. 
Purge fans shall also respond automatically to the 
refrigerant concentration detection system set to 
activate the ventilation system at no more than 25 
percent of the LFL, or 50 percent of the IDLH, or a 
measure equivalent thereto, whichever is less. An 
emergency purge control shall be provided with a 
manual reset only. 

1108.6 Central Control of Ventilation Systems. 

Mechanical ventilation systems shall have switches 
to control power to each fan. The switches shall be 
key operated or within a locked, glass-covered 
enclosure at an approved location adjacent to and 
outside of the principal entrance to the machinery 
room. Necessary keys shall be located in a single 
approved location. Switches controlling fans 
providing continuous ventilation shall be of the two- 
position, on-off type. Switches controlling fans 
providing intermittent or emergency ventilation 
shall be of the three-position, automatic on-off type. 
Switches shall be labeled identifying both the 
function and the specific fan controlled. Two colored 
and labeled indicator lamps responding to the 
differential pressure created by airflow shall be 
provided for each switch. One lamp shall indicate 
flow; the other shall indicate no flow. 

1108.7 Ventilation Discharge. Exhaust from 
mechanical ventilation systems shall be discharged 
at least twenty (20) feet (6,096 mm) from a property 
line or openings into buildings. Discharges capable 
of exceeding 25 percent of the LFL, or 50 percent of 
the IDLH, shall be equipped with approved 
treatment systems to reduce the discharge 
concentrations to these values or lower. 

Exception: When an approved engineering 
analysis of plume dispersion demonstrates that 
the limiting values will not be exceeded at the 
property line. 

1108.8 Fans. Fans and associated equipment 
intended to operate the emergency purge of other 
than Group Al or Group Bl refrigerants shall meet 
the requirements for a Class I, Division 1 hazardous 
location as specified in the Electrical Code. 

1108.9 Ventilation Intake. Makeup air intakes to 
replace the exhaust air shall be provided to the 
refrigeration machinery room directly from outside 
the building. Intakes shall be located as required by 
other sections of the code and fitted with backdraft 



dampers or similar approved flow-control means to 
prevent reverse flow. Distribution of makeup air 
shall be arranged to provide thorough mixing within 
the refrigeration machinery room to prevent short 
circuiting of the makeup air directly to the exhaust. 

1109.0 Refrigeration Machinery Room Equipment 
and Controls. 

1109.1 General. Equipment, piping, ducts, vents, or 
similar devices that are not essential for the 
refrigeration process, maintenance of the equipment, 
or for the illumination, ventilation, or fire protection 
of the room shall not be placed in or pass through a 
refrigeration machinery room. 

Equipment essential to the refrigeration process 
often includes, but is not always limited to, the 
following: 

1 1 09.1 .1 Refrigeration compressors. 

1 1 09.1 .2 Condensing units. 

1 1 09.1 .3 Pumps, associated piping, and automatic 
control valves for refrigerant, condenser water, 
and brine or chilled water. 

1109.1.4 Refrigeration control devices and 
panels. 

1 1 09.1 .5 Machinery room ventilation equipment 
(see Section 1108.0). 

1109.1.6 Cooling towers or portions thereof (see 
Chapter 11, Part n). 

1 1 09.1 .7 Refrigerant receivers and accumulators. 

1 1 09.1 .8 Refrigerant vapor-detection and alarm 
systems (see Section 1121.0). 

1109.1.9 Machinery room fire sprinkler system 
exclusive of its shutoff valves. 

1109.1.10 Machinery room lighting and service 
receptacles. 

1109.1.11 Motor control centers and electrical 
panels for machinery room systems. 

1109.2 Electrical. Electrical equipment and installa- 
tions shall comply with the Electrical Code. The 
refrigeration machinery room shall not be required 
to be a hazardous (classified) location except as 
provided in Section 1108.8. 

1 1 09.3 Storage. Storage of materials in a refrigera- 
tion machinery room shall be as permitted in the Fire 
Code. 

1109.4 Emergency Control. A clearly identified 
switch of the break-glass type providing "off-only 
control of electrically energized equipment and 
devices within the refrigeration machinery room 
shall be provided immediately adjacent to and 



179 



1109.4-1112.1 



2007 CALIFORNIA MECHANICAL CODE 



outside of each refrigeration machinery room exit. In 
addition, emergency shutoff shall also be 
automatically activated when the concentration of 
refrigerant vapor exceeds 25 percent of the LFL. 

1110.0 Refrigerant Piping, Containers, and Valves. 

1110.1 General. Materials used in the construction 
and installation of refrigeration systems shall be 
suitable for the refrigerant, refrigerant oU, or brine in 
the system. Material or equipment that will 
deteriorate due to the chemical action of the 
refrigerant, the oil, or combination of both, shall not 
be installed. 

1110.2 Nonferrous IWaterials. Copper and brass 
refrigeration piping, valves, fittings, and related 
parts used in the construction and installation of 
refrigeration systems shall be approved for the 
intended use. 

1 1 1 0.3 Ferrous IWaterials. Iron and steel refrigeration 
piping, valves, fittings, and related parts shall be 
approved for the intended use. Pipe more than two 
(2) inches (50 mm) iron pipe size shall be electric- 
resistance welded or seamless pipe. 

1111.0 Erection of Refrigerant Piping. 

1111.1 General. Piping and tubing shaU be installed 
so as to prevent vibration and strains at joints and 
connections. 

1 1 1 1 .2 Support. In addition to the requirements of 
Section 1106.2, piping and tubing shall be securely 
fastened to a permanent support within six (6) feet 
(1,829 mm) following the first bend in such tubing 
from the compressor and within two (2) feet (610 
mm) of each subsequent bend or angle. Piping and 
tubing shall be supported at points not more than 
fifteen (15) feet (4,572 mm) apart. 

1111.3 Protection from Damage. Refrigerant 
piping and tubing shall be installed so that it is not 
subject to damage from an external source. Soft 
annealed copper tubing shall not be larger than 
1-3/8 inch (35 mm) nominal size. Mechanical joints 
shall not be made on tubing larger than 3/4 inch (20 
mm) nominal size. Soft annealed copper tubing 
conveying refrigerant shall be enclosed in iron or 
steel piping and fittings, or in conduit, molding, or 
raceway that wUl properly protect the tubing against 
mechanical injury from an exterior source. 

Exceptions: 

(1) Tubing entirely within or tubing within five 
(5) feet (1,524 mm) of a refrigerant compressor 
when so located that it is not subject to 
external injury. 



(2) Copper tubing serving a dwelling unit, 
when such tubing contains Group Al 
refrigerant and is placed in locations not 
subject to damage from an external source. 

1111.4 Visual Inspection. Refrigerant piping and 
joints shall be exposed to view for visual inspection 
and acceptance by the Authority Having Jurisdiction 
prior to being covered or enclosed. 

Exception: Copper tubing enclosed in iron or 
steel piping conduit, molding, or raceway, 
provided there are no fittings or joints concealed 
therein. 

1111.5 Prohibited Locations. Refrigerant piping 
shall not be located within a required exit. 

1111.6 Underground Piping. Refrigerant piping 
placed underground shall be protected against 
corrosion. 

1111.7 Joints. Iron or steel pipe joints shall be of 
approved threaded, flanged, or welded types. 
Exposed threads shall be tinned or coated with an 
approved corrosion inhibitor. Copper or brass pipe 
joints of iron pipe size shall be of approved threaded, 
flanged, or brazed types. Copper tubing joints and 
connections shall be approved flared, lapped, 
swaged, or brazed joints. 

1111.8 Identification. Piping shall meet the 
reference standard for identification. The type of 
refrigerant, function, and pressure shall be indicated. 

1112.0 Refrigerant Control Valves. 

1 1 1 2.1 Location. Stop valves shall be installed in the 
refrigerant piping of a refrigeration system at the 
following locations: 

1112.1.1 At the inlet and outlet of a positive- 
displacement-type compressor, compressor unit, 
or condensing unit. 

1112.1.2 At the refrigerant outlet from a liquid 
receiver. 

1112.1.3 At the refrigerant inlet of a pressure 
vessel containing liquid refrigerant and having 
an internal gross volume exceeding three (3) 
cubic feet (108 m^). 

Exceptions: 

(1) Systems with nonpositive-displacement 
compressors. 

(2) Systems having a puntip-out receiver for 
storage of the charge. 

(3) Systems containing less than 110 
pounds (49.9 kg) of Group Al refrigerant. 

(4) Self-contained systems that do not 



180 



REFRIGERATION 



1112.1-1114.6 



require a stop valve at the inlet of the 
receiver. 

1112.2 Support. Stop valves iristalled in copper 
refrigerant lines of 3/4 inch (20 mm) or less outside 
diameter shall be securely supported independently 
of the tubing or piping. 

Ill 2.3 Access. Stop valves required by this section 
shall be readily accessible from the refrigeration 
machinery room floor or a level platform. 

1112.4 Identification. Stop valves shall be identified 
by tagging in accordance with the reference standard 
for identification. A valve chart shall be mounted 
under glass at an approved location near the 
principal entrance to a refrigeration machinery room. 

1113.0 Pressure-Limiting Devices. 

1113.1 Wlien Required. Pressure-limiting devices 
shall be provided on all systems operating above 
atmospheric pressure. 

Exception: Factory-sealed systems containing 
less than twenty-two (22) pounds (9.98 kg) of 
Group Al refrigerant listed by art approved 
agency. 

1113.2 Setting. The maximum setting to which a 
pressure-limiting device may be set by use of the 
adjusting means provided shall not exceed the design 
pressure of the high side of a system not protected by 
a pressure-relief device or 90 percent of the pressure 
setting of the pressure-relief device installed on the 
high side of a system. 

Exception: In systems using other than positive- 
displacement compressors that are protected by 
a pressure-relief device, the setting may be the 
design pressure of the high side of the system, 
provided the pressure-relief device is located in 
the low side, subject oiJy to low-side pressure, 
and there is a permanent, unvalved relief path 
between the high side and the low side of the 
system. 

1 1 1 3.3 Connection. Pressure-limiting devices shall 
be connected between the pressure-imposing 
element and stop valve on the discharge side 
without intervening stop valves in the line leading to 
the pressure-limiting device. 

1113.4 Operation. When the system is protected 
by a pressure-relief device, the pressure-limiting 
device shall stop the action of the pressure- 
imposing element at a pressure not more than 90 
percent of the setting of the pressure-relief device. 

1 11 4.p Pressure-Relief Devices. 

1114.1 General. Refrigeration systems shall be 



protected by a pressure-relief device or other means 
designed to safely relieve pressure due to fire or 
abnormal conditions. 

1114.2 Positive-Displacement Compressor. A 

positive-displacement compressor shall be equipped 
by the manufacturer with a pressure-relief device of 
adequate size and pressure setting to prevent 
rupture of the compressor or other component 
located between the compressor and the stop valve 
on the discharge side. 

1114.3 Liquid-Containing Portions of Systems. 

Liquid-containing portions of systems, including 
piping, that can be isolated from pressure-relief 
devices required elsewhere and that can develop 
pressures exceeding their working design pressures 
due to temperature rise, shall be protected by the 
installation of pressure-relief devices. 

1114.4 Evaporators. Evaporators located within 
eighteen (18) inches (457 mm) of a heating element or 
coil shall be fitted with a pressure-relief device. 

Exceptions: 

(1) Self-contained equipment. 

(2) Factory-built coil assemblies specifically 
designed for installation on the discharge of 
forced-air heating units. 

(3) If the connected and unvalved volume of 
the low side of the system meets the following: 
Vl > [Wl - (V2 - Vl) / Vgt ] Vgc (Equation 11-5) 

WHERE: 

Vl = low-side volume, cubic feet. 

V2 = total volume of system, cubic feet. 

Wl = total weight of refrigerant in system, 
poxmds. 

Vgt = specific volume of refrigerant vapor at 
110°F (43°C), cubic feet per pound. 

Vgc = specific volume at critical temperature 
and pressure, cubic feet per pound. 

(4) Reheat coils using the refrigerant for heait 
recovery. 

1114.5 Actuation. Pressure-relief devices shall be 
direct-pressure actuated. Each part of a refrigeration 
system that can be valved off and that contains one 
or more pressure vessels having interfial diameters 
greater than six (6) inches (150 mm) and containing 
liquid refrigerant shall be protected by a pressure- 
relief device. 

1114.6 Stop Valves Prohibited. Stop valves shall 
not be located between a pressure-relief device and 
the portion of the system protected thereby. 



181 



1114.7-1117.7 



2007 CALIFORNIA MECHANICAL CODE 



1114.7 Location. Pressure-relief devices shall be 
connected as nearly as practical to the portion of the 
system protected thereby, above the Uqtdd refrigerant 
level, and accessible for inspection and repair. 

Exception: Fusible plugs on the high side may 
be located above or below the liquid refrigerant 
level. 

1114.8 Materials. Seats and discs of pressure-relief 
devices shall be constructed of suitable material to 
resist corrosion or other chemical action caused by the 
refrigerant. Seats and discs of cast iron are prohibited. 

1115.0 Pressure-Relief Device Settings. 

1115.1 Pressure-Relief Valve Setting. Pressure-reUef 
valves shall actuate at a pressure not exceeding the 
design pressure of the parts of the system protected. 

1115.2 Rupture Member Setting. Rupture members 
used in lieu of, or in series with, a relief valve shall 
have a nominal rated rupture pressure not exceeding 
the design pressure of the parts of the system 
protected. Rupture members installed ahead of relief 
valves need not be larger, but shall not be smaller, 
than the relief-valve inlet. 

1116.0 Marking of Pressure-Relief Devices. 

1116.1 Pressure-Relief Valves. Pressure-relief 
valves for refrigerant-containing components shall 
be set and sealed by the manufacturer or by an 
approved assembler. Pressure-relief valves shall be 
marked by the manufacturer with the data required 
to show compliance with this chapter. 

Exception: Relief valves for systems with design 
pressures of fifteen (15) psig (103.35 kPa) or less 
may be marked by the manufacturer with 
pressure-setting capacity. 

1116.2 Rupture Members. Rupture members for 
refrigerant pressure vessels shall be marked with the 
data required to show compliance with this chapter. 

1116.3 Fusible Plugs. Fusible plugs shall be 
marked with the melting temperatures in °F (°C) to 
show compliance with this chapter. 

1117.0 Overpressure Protection. 

1 1 17.1 General. Pressure vessels shall be provided with 
over-pressure protection as required by this section. 

1117.2 Type of Protection. Pressure vessels with 
three (3) cubic feet (0.085 m') internal gross voltmie or 
less may use a single pressure-relief device or a fusible 
plug. Presstire vessels over three (3) cubic feet (0.085 
m^) but less than ten (10) cubic feet (0.283 m^) internal 
gross volume may use a single pressure-relief device 



but not a fusible plug. Pressure vessels of ten (10) cubic 
feet (0.283 m^) or more internal gross voltime shall use 
a single rupture member or dual pressure-relief valve. 

1117.3 Three-Way Valve Required. When dual 
pressure-relief valves are used, they shall be installed 
with a three-way valve to allow testing or repair. 

Exception: A single relief valve of the required 
relieving capacity may be used on low-side 
pressure vessels of ten (10) cubic feet (0.283 m') or 
more when meeting the requirements of Section 
1117.8, Exception 2. 

1117.4 Parallel Pressure-Relief Devices. Two or 

more pressure-relief devices in parallel to obtain the 
required capacity shall be considered as one 
pressure-relief device. The discharge capacity shall 
be the sum of the capacities required for each 
pressure vessel being protected. 

1117.5 Discharge Capacity. The minimum required 
discharge capacity of pressure-relief devices for each 
presstire vessel shall be determined by the following: 



C=/DL 



(Equation 11-6) 



WHERE: 

C = minimum required discharge capacity of the 
relief device in pounds of air per minute. 

D = outside diameter of vessel, feet. 
L = length of vessel, feet. 

/= factor dependent upon type of refrigerant from 
Table 11-3. 

1117.6 Rating of Pressure-Relief Valves. Pressure- 
relief valves shall be of approved types and 
capacities. The rated discharge capacity of a 
pressure-relief valve shall be expressed in poimds of 
air per minute. Pipe and fittings between the 
pressure-relief valve and the parts of the system it 
protects shall have at least the area of the pressure- 
relief valve inlet. 

1117.7 Rating of Rupture Members and Fusible 
Plugs. The rated discharge capacity of a rupture 
member or fusible plug discharging to atmosphere 
under critical flow conditions in pounds of air per 
minute shall be determined by the following 
formulas: 

C = 0.8Pi/ (Equation 11-7) 



d = 1.12VC7P7 



(Equation 11-8) 



182 



REFRIGERATION 



1117.7-1119.3 



WHERE: 

C = rated discharge capacity of air, pounds per 
minute. 

d = smallest internal diameter of the inlet pipe, 
retaining flanges, fusible plug, rupture 
member, inches. 

For rupture members: 

Pj= (rated pressure psig X 1.1) + 14.7 (Equation 11-9) 

For fusible plugs: 

Pj = absolute saturation pressure, corresponding to 
the stamped temperature melting point of the 
fusible plug or the critical pressure of the 
refrigerant used, whichever is smaller, psia. 

1117.8 Discharge Location. Pressure-relief devices 
shall discharge to the atmosphere unless otherwise 
prohibited by this chapter at a location at least fifteen 
(15) feet (4,572 mm) above the adjoining grade level 
and at least twenty (20) feet (6,096 mm) from an 
opening into a building. The discharge termination 
shall be fitted with an approved diffuser directed to 
prevent spray of discharged refrigerant on personnel 
or entry of foreign material or water into the 
discharge piping. Discharge piping connected to the 
discharge side of a fusible plug or rupture member 
shall have provisions to prevent internal plugging of 
the pipe caused by the fusible plug or rupture- 
member function. 

Exceptions: 

(1) Systems containing less than 110 pounds 
(49.9 kg) of a Group Al refrigerant. 

(2) A pressure-relief valve may discharge into 
the low side of the system if the pressure- 
relief valve is of a type not affected by back 
pressure, provided the low side is equipped 
with pressure-relief devices of equal 
relieving capacity. The low-side pressure- 
relief device shall be set and discharged as 
required by this section. Fusible plugs or 
rupture members shall not be used for 
pressure relief into the low side. 

1118.0 Discharge Piping. 

The area of the discharge pipe from the pressure- 
relief device or fusible plug shall be at least as large 
as the outlet area of the pressure-relief device or 
fusible plug. A discharge pipe accepting discharge 
from more than one relief device or fusible plug shall 
be sized and have a maximum length of the common 
discharge not less than that required by the sum of 
the .rated capacities of all relief valves discharging 
into the header at the lowest pressure setting of any 



of the relief valves discharging into the header. 

The maximum length of the discharge piping 
permitted to be installed on the outlet of a pressure- 
relief device shall be determined by: 



L = 9pV/16Cf 



(Equation 11-10) 



WHERE: 

C = minimum required discharge capacity, pounds 
of air per minute. 

d = internal diameter of pipe, inches. 

L = length of discharge pipe, feet. 

For relief valves and rupture disks: 
P = (rated pressure psig x 1.1) + 14.7 (Equation 11-11) 

For fusible plugs P= Pj where: 

Pj = absolute saturation pressure corresponding 
to the stamped temperature melting point of the 
fusible plug or the critical pressure of the refrigerant 
used, whichever is smaller, psia. 

1119.0 Speciai Discharge Requirements. 

1119.1 Generai. Systems containing other than 
Group Al or Bl refrigerants shall discharge to 
atmosphere only through an approved flaring device. 

Exceptions: 

(1) Ammonia systems complying with Section 
1120.0. 

(2) Ammonia absorption systems serving a 
single dwelling unit. 

(3) When the Authority Having Jurisdiction 
determines upon review of a rational 
engineering analysis that significant fire, 
health, or envirorunental hazard would not 
result from the proposed atmospheric 
release. 

(4) Lithium bromide absorption system using 
water as the refrigerant. 

1119.2 Design Requirements. Flaring devices shall 
be designed to incinerate the entire discharge. The 
products of refrigerant incineration shall not pose 
health or environmental hazards. Incineration shall 
be automatic upon initiation of discharge, shall be 
designed to prevent blow-back, and shall not expose 
structures or materials to threat of fire. Standby fuel, 
such as LPG, and standby power shall have the 
capacity to operate for 1.5 times the required time for 
complete incineration of the charge. 

1119.3 Testing. Flaring systems shall be tested to 
demonstrate their safety and effectiveness. A report 



183 



1119.3-1123.2 



2007 CALIFORNIA MECHANICAL CODE 



from an approved agency shall be subrrutted detailing 
the emission products from the system as installed. 

1120.0 Ammonia Discharge. 

Ammorua shall discharge into a tank of water that 
shall be used for no purpose except ammonia 
absorption. At least one (1) gallon (3.785 L) of fresh 
water shall be provided for each pound (454 g) of 
ammonia in the system. The water used shall be 
prevented from freezing without the use of salt or 
chemicals. The tank shall be substantially constructed 
of not less than 1/8 inch (3.2 mm) or No. 10 MSG 
steel. The horizontal dimensions of the tank shall be 
equal to or less than one-half the height. The tank 
shall have a hinged cover or, if of the enclosed type, 
shall have a vent hole at the top. Pipe connections 
shall be through the top of the taiik. The discharge 
pipe from the pressure-relief valves shall discharge 
ammonia in the center of the tank near the bottom 
but not more than thirty (30) feet (9,144 mm) below 
the surface of the water. 

Exception: An ammonia-water absorption unit 
system installed outdoors serving a dwelling 
unit, provided the discharge is shielded and 
dispersed. 

1121.0 Detection and Alarm Systems. 

1121.1 General. When required by this chapter, 
approved refrigerant-vapor detection and alarm 
systems shall utilize alarm signaling devices 
providing a sound pressure level of at least 15 dB 
above the operating ambient noise sotind pressure 
level of the space in that they are installed and 
providing an approved, distinctive visual alarm. 
Alarms shall be activated within the space and as 
required in Section 1121.3 whenever the refrigerant 
vapor PEL is exceeded. In other than machinery 
rooms, such systems shall also automatically stop the 
flow of refrigerant to evaporators within the space 
and stop the flow of refrigerant in all supply lines 
leaving the machinery room whenever the refrigerant 
vapor concentration is detected at or above 50 
percent of the IDLH or 25 percent of the LEL. 
Detection of refrigerant vapor concentrations at or 
above 25 percent of the LEL shall automatically de- 
energize all electrical power within the space that 
does not meet the requirement for a Class I, Division 
1, Group D electrical installation. 

1121.2 Power and Supervision. Detection and 
alarm systems shall be powered and supervised as 
required for fire alarm systems in the Fire Code. 

1121.3 Annunciation. Detection and alarm systems 



shall be annunciated for all refrigerants at an 
approved location in accordance with the Fire Code. 

1121.4 Installation, Maintenance, and Testing. 

Detection and alarm systems shall be installed, 
maintained, and tested in accordance with the Fire Code. 

1122.0 Equipment Identification. 

In addition to labels required elsewhere in this code, 
a refrigeration system shall be provided with labels 
compljdng with the requirements of this section. 

1 122.1 A condenser, receiver, absorber, accumulator, 
and similar equipment having an internal volume of 
more than three (3) cubic feet (0.085 m') and 
containing refrigerant shall be equipped with a 
permanent label setting forth the type of refrigerant 
in such vessel. 

1122.2 In a refrigeration machinery room and for a 
direct refrigerating system of more than ten (10) 
horsepower (7.457 kW), there shall be a permanent 
sign at an approved location giving the following 
information: 

1122.2.1 Name of contractor installing the 
equipment. 

1 1 22.2.2 Name and number designation of 
refrigerant in system. 

1 1 22.2.3 Pounds of refrigerant in system. 

1123.0 Testing of Refrigeration Equipment. 

1 1 23.1 Factory Tests. Refrigerant-containing parts 
of units shall be tested and proved tight by the 
manufacturer at the design pressure for which they 
are rated. The test pressure applied to the high side 
of each factory-assembled refrigeration system shall 
be equal to the design pressure of the high side. The 
test pressure applied to the low side of each factory- 
assembled refrigeration system shall be equal to the 
design pressure of the low side. 

Exception: Units with a design pressure of 
fifteen (15) psig (103.42 kPa) or less shall be 
tested at a pressure not less than 1.33 times the 
design pressure. 

1 123.2 Field Tests. Refrigerant-containing parts of a 
system that is field-erected shall be tested and 
proved tight to the Authority Having Jurisdiction 
after complete installation and before operation. The 
high and low sides of each system shall be tested and 
proved tight at not less than the lower of the 
pressure in Table 11-4 or the setting of the pressure- 
relief device. 

Exceptions: 

(1) Compressors, condensers, evaporators. 



184 



REFRIGERATION 



1123.2 -1133.0 



coded pressure vessels, safety devices, 
pressure gauges, control mechanisms, and 
systems that are factory tested. 

(2) Refrigeration systems containing Group R- 
22, not exceeding five (5) tons of refrigeration 
capacity (17.58 kW), and field-piped using 
approved, factory-charged line sets may be 
proved tight by observing retention of 
pressure on a set of charging gauges and 
soaping connections while the system is 
operating. 

1123.3 Test Medium. Oxygen, flammable or combus- 
tible gases, or gas mixtures shall not be used for leak 
testing. The means used to build up the test pressure 
shall have either a pressure-limiting device or a 
pressure-reducing device with a pressure-relief 
device and a gauge on the outlet side. The pressure- 
relief device shall be set above the test pressure but 
low enough to prevent permanent deformation of 
system components. 

1 1 23.4 Declaration. A dated declaration of test shall 
be provided for systems containing fifty-five (55) 
potinds (24.95 kg) or more of refrigerant. The decla- 
ration shall give the name and number designation 
of the refrigerant and the field test pressure applied 
to the high side and the low side of the system. The 
declaration of test shall be signed by the installer. 

1123.5 Brine Systems. Brine-containing portions of 
a system shall be tested at 1.5 times the design 
pressure of the system using brine as the test fluid. 

1 1 24.0 iVIaintenance and Operation. 

Refrigeration systems shall be operated and main- 
tained as required by the Fire Code. 



coolers shall be supported on noncombustible 
grillage designed in accordance with the Building 
Code. Seismic restraints shall be as required by the 
Building Code. 

1128.0 Water Supply. 

Water supplies and backflow protection shall be as 
required by the Uniforni Plumbing Code. 

1129.0 Drainage. 

Drains, overflows, and blow-down provisions shall 
have an indirect connection to an approved disposal 
location. Discharge of chemical waste shall be as 
approved by the appropriate regulatory authority. 

1130.0 Cliemical Treatment Systems. 

Chemical treatment systems shall comply with the 
Fire Code. When chemicals used present a contact 
hazard to personnel, approved emergency eye-wash 
and shower facilities shall be installed. 

1131.0 Location. 

Cooling towers, evaporative condensers, and fluid 
coolers shall be located such that their plumes cannot 
enter occupied spaces. Flume discharges shall be at 
least five (5) feet (1,524 mm) above or twenty (20) 
feet (6,096 mm) away from any ventilation inlet to a 
building. Location on the property shall be as 
required for buildings by the Building Code. 

1131.1 [For OSHPD 1,2, 3 & 4] Plume discharge shall 
he at least twenty-five (25) feet (7620 mm) from any 
ventilation inlet to a building. 



1125.0 Storage of Refrigerants and Refrigerant Oils. 

Refrigerants and refrigerant oils not charged within 
the refrigeration system shall be stored as required 
by the Fire Code. 

Part II - Cooling Towers 



1132.0 Electrical. 

Electrical systems shall be in accordance with the 
Electrical Code. Equipment shall be provided with a 
vibration switch to shut off fans operating with 
excessive vibration. In climates comxnonly subject to 
electrical storms, lightning protection shall be 
provided on roof-mounted equipment. 



1126.0 General. 

Cooling towers, evaporative condensers, and fluid 
coolers shall be readily accessible. When located on 
roofs, such equipment having combustible exterior 
surfaces shall be protected with an approved 
automatic fire-extinguishing system. 

1127.0 Support and Anchorage. 

Cooling towers, evaporative condensers, and fluid 



1133.0 Refrigerants and Hazardous Fluids. 

Equipment containing refrigerants as a part of a 
closed-cycle refrigeration system shall comply with 
Part I of this chapter. Equipment containing other 
fluids that are flammable, combustible, or hazardous 
shall comply with the Fire Code. 



185 



Table 11-1 



2007 CALIFORNIA MECHANICAL CODE 



TABLE 11-1 

Refrigerant GroupsS PropertiesS and Allowable Quantities^' " 

(Data reprinted with permission from The American Society of Heating, Refrigerating, and Air- 

Conditioning Engineers) 















Pounds 


Refrig- 


Chemical 


Chemical Name* 


Safety 


PEU 


IDLH' 


per 1,000 cf 


erant 


Formula 


(Composition for Blends) 


Group' 


(ppm) 


(ppm) 


of Space' 


R-11 


CCI3F 


Trichlorofluoromethane 


Al 


ClOOO" 


4,000"' 


1.60 


R-12 


CCI2F2 


Dichlorodifluoromethane 


Al 


1,000 


40,000 


12.00 


R-13 


CCF3 


Chlorotrifluoromethane 


Al 


1,000 


67,000 


18.00 


R-13B1 


CBrFa 


Bromofcrifluoromethane 


Al 


1,000 


57,000 


22.00 


R-22 


CHCIF2 


Chlorodifluoromethane 


Al 


1,000'° 


42,000" 


9.4 


R-23 


CHF3 


Trlfluoromethane 


Al 


~ 


~ 


- 


R-113 


CCI2FCCIF2 


l,l,2-trichloro-lA2 
-trifluoroethane 


Al 


1,000 


4,500 


1.90 


R-114 


CCIF2CCIF2 


l,2-dichloro-l,l,2,2 
-tetraflouroethane 


Al 


1,000 


50,000 


9.40 


R-123 


CHCI2CF3 


2,2-dichloro-l,14r 
-trifluoroethane 


Bl 


1,010 


4,000" 


1.60 


R-124 


CHCIFCF3 


2-chloro-l,l,l/2 
-tetrafluoroethane 


Al 


- 


- 


- 


R-134a 


CF3CH2F 


1,1,1/2-tetrafluoroethane 


Al 


1,000'» 


50,000" 


16.00 


R-170 


CH3CH3 


Ethane 


A3 


1,000 


6,400 


0.50 


R-236fa 


CF3CH2CF3 


1,1,1,3,3,3-hexafluoropropane 


Al 


- 


- 


- 


R-245fa 


CF3CH2CHF2 


1,1/1/3,3-pentafIuoropropane 


A3 


~ 


- 


- 


R-290 


CH3CH2CH3 


Propane 


A3 


1,000 


4,400 


0.50 


R-400 


azeotrope 


R-12/114 


Al 


- 


~ 


- 


R-401A 


azeotrope 


R-22/152a/.124 (53/13/34) 


Al 


- 


- 


- 


R-401B 


azeotrope 


R-22/152a/124 (61/11/28) 


Al 


- 


- 


- 


R-401C 


azeotrope 


R-22/152a/124 (33/15/52) 


Al 


~ 


~ 


- 


R-402A 


azeotrope 


R-125/290/22 (60/2/38) 


Al 


~ 


~ 


- 


R-402B 


azeotrope 


R-125/290/22 (38/2/60) 


Al 


~ 


- 


- 


R-404A 


azeotrope 


R-125/143a/134a (44/52/4) 


Al 


-- 


- 


- 


R-407A 


azeotrope 


R-32/125/134a (20/40/40) 


Al 


- 


- 


- 


R-407B 


azeotrope 


R-32/125/134a (10/70/20) 


Al 


- 


- 


- 


R-407C 


azeotrope 


R-32/125/134a (23/25/52) 


Al 


~ 


~ 


- 


R-407D 


azeotrope 


R-32/125/134a (15/15/70) 


Al 


~ 


~ 


- 


R-407E 


azeotrope 


R-32/125/134a (25/15/60) 


Al 


~ 


~ 


~ 


R-408A 


azeotrope 


R-125/143a/22 (7/46/47) 


Al 


~ 


~ 


- 


R-409A 


azeotrope 


R-22/124/142b (60/25/15) 


Al 


~ 


~ 


- 


R-410A 


azeotrope 


R-32/125 (50/50) 


Al 


- 


- 


- 


R-416A 


azeotrope 


R-134a/124/600 (59/39.5/1.5) 


Al 


- 


- 


- 



186 



REFRIGERATION 



Table 11-1 continued 



Table 11-1 {Continued) 
Refrigerant Groups^ Properties^ and Aliowable Quantities^ 



R-500 


azeotrope 


R-12/152a (73.8/26.2) 


Al 


1,000>» 


47,000'» 


12.00 


73.8% 


CCI2F2 


Dichlorodifluoromethane 










26.2% 


CH3CHF2 


1,1-difluoroethane 










R-502 


azeotrope 


R-22/115(48.8/51.2) 


Al 


1,000'° 


65,000" 


19.00 


48% 


CHCIF2 


Chlorodifluoromethane 










51.2% 


CCIF2CF3 


l-chloro-1,1,2,2,2 
-pentafluoroethane 










R-503 


azeotrope 


R-23/13 (48.8/51.2) 


Al 


1,000 


67,000 


15.00 


R-507A 


azeotrope 


R-125/143a (50/50) 


Al 


- 


- 


-- 


R-508A 


azeotrope 


R-23/116 (39/61) 


Al' 


- 


- 


- 


R-508B 


azeotrope 


R-23/116 (46/54) 


Al 


- 


- 


-- 


R509A 


azeotrope 


R-22/218 (44/56) 


Al 


- 


- 


-- 


R-600 


CH3CH2CH2CH3 


Butane 


A3 


800 


3,400 . 


0.51 


R-600a 


CH(CH3)2CH3 


Isobutane (2-methyl propane) 


A3 


800 


3,400 


0.51 


R-717 


NH3 


Ammonia 


B2 


5,012 


500 


0.022 


R-718 


H2O 


Water 


Al 


- 


- 


- 


R-744 


CO2 


Carbon Dioxide 


Al 


5,000 


50,000 


5.70 


R-1150 


CH2=CH2 


Ethene (ethylene) 


A3 


1,000 


5,200 


0.38 1 


R-1270 


CH3CH=CH2 


Propene (propylene) 


B3 


1,000 


3,400 ■ 


0.37 



For SI: 1 pound = 0.454 kg, 1 cubic foot = 0.0283m^ 

' Refrigerant safety group designation is in accordance with Section 1102.0. 

^ Refrigerant properties are those needed for this chapter. 

' Allowable quantities are for high-probability systems under Section 1103.0 only. 

•" Chemical name shown is the preferred name. 

= PEL is that designated in 29 CFR 1910.1000 unless otherwise indicated. 

' IDLH is that designated by NIOSH imless otherwise designated. 

' Pounds of refrigerant in a high-probability system per 1,000 cubic feet (28.3 kg/m') of occupied space. See Section 1104.0. 

This column does not apply to refrigerant machinery rooms or areas covered by Section 1106.0. 
' The PEL value shown is the TLV-C recommended by ACGIH. 

' The IDLH value shown is reduced from that designated by NIOSH in light of cardiac sensitization potential. 
'° A PEL has not yet been established; the value given was determined in a consistent manner. 
" An IDLH has not yet been established; the value given was determined in a consistent manner. 
« OSHA PEL is 50 ppm; ACGIH TLV-TWA is 25 ppm. 
" [Fot OSHPD 1, 2 & 4] The quantity of refrigerant in each system is limited to 50% of the amount listed. Exception: kitchens, 

laboratories, and mortuaries. 



187 



Table 11-2 



2007 CALIFORNIA MECHANICAL CODE 





TABLE 11-2 








Permissible Refrigeratior 


1 Systems^ 




Occupancy Group 


Higii-Probability Low-Probability 


■Machinery 


and Division 


System 


System 


Room 


A-l 


Group Al only 


Any 


Any 


A-2.1 


Group Al only 


Any 


Any 


A-3 


Group Al only 


Any 


Any 


A-^ 


Group Al only 


Any 


Any 


B 


Group Al only^ 


Any 


Any 


E-1 


Group Al only 


Any 


Any 


E-2 


Group Al only 


Any 


Any 


E-3 


Group Al only 


Any 


Any 


F-1 


Group Al orUy^ 


Any 


Any 


F-2 


Any^ 


Any 


Any 


H-1 


Any 


Any 


Any 


H-2 


Any 


Any 


Any 


H-3 


Any 


Any 


Any 


H-4 


Group Al only 


Any 


Any 


H-5 


Group Al only 


Any 


Any 


H-6 


Group Al only 


Any 


Any 


H-7 


Any 


Any 


Any 


I-l.l 


None 


Any 


Any 


1-1.2 


Group Al orUy 


Any 


Any 


1-2 


Group Al only 


Any 


Any 


1-3 


None 


Any 


Any 


M 


Group Al only^ 


Any 


Any 


R-1 


Group Al only 


Any 


Any 


R-2 


Group Al only 


Any 


Any 


R-3 


Group Al only 


Any 


Any 


S-1 


Group Al only^ 


Any 


Any 


S-2 


Any^ 


Any 


Any 


S-3 


Group Al only 


Any 


Any 


S-4 


Group Al only 


Any 


Any 


S-5 


Group Al only 


Any 


Any 


U-1 


Any 


Any 


Any 


U-2 


N/A 


N/A 


N/A 



Note: N/A — Not applicable. 

•See Section 1105.0. 

^Any refrigerant may be used within a high-probability system when the room or space complies with Section 1105.3. 



188 



REFRIGERATION 



Table 11 -3 -Table 11 -4 



TABLE 11-3 
Value of for Equation 11-6 



Refrigerant Number 



/ 



11 
12 
22 
113 
114 
115 
123 
134a 
152a 
500 
502 
717 
744 



1.0 
1.6 
1.6 
1.0 
1.6 
2.5 
1.0 
1.6 
1.0 
1.6 
2.5 
0.5 
1.0 



TABLE 11-4 
Field Leal< Test Pressures in psig (kPa) 



Refrigerant 
Number 



High Side 
Water Cooled 



High Side 
Air Cooled 



Low Side 



11 


15 


35 


15 


12 


140 


220 


140 


22 


230 


360 


230 


113 • 


15 


15 


15 


114 


40 


80 


40 


115 


275 


340 


275 


123 


15 


30 


15 


134a 


150 


250 


150 


152a 


130 


220 


130 


500 


165 


265 


165 


502 


250 


385 


250 


717 


235 


390 


235 


744* 


N/A 


N/A 


N/A 



Note: psi x 6.89476 = kPa, N/A— Not applicable. 

'Special design required; test pressures typically exceed 1,000 psig (6890 kPa). 



189 



2007 CALIFORNIA MECHANICAL CODE 



190 



CHAPTER 12 



HYDRONICS 



Part I - Steam and Water Piping 

1201.0 Scope. 

Steam and water piping systems that are part of a 
heating or cooUng system shall comply with the 
following requirements: 

1201.1 Those portions of piping systems in which 
the pressure exceeds 160 psig (1,103 kPa) or the 
temperature exceeds 250°F (121°C) shall comply with 
nationally recognized standards and the require- 
ments of Section 1201.2. 

1201.2 Those portions of piping systems in which 
the pressure does not exceed 160 psig (1,103 kPa) 
and the temperature does not exceed 250°F (121 °C) 
shall comply with the following requirements: 

1201.2.1 IVIaterlais and Construction. 

1 201 .2.1 .1 Pipe. Pipe shall be brass, copper, 
cast iron, galvanized or black wrought iron, 
galvanized or black steel, or other approved 
materials. 



Tubing shall be copper 



1201.2.1.2 Tubing. 

water tube. 

1201.2.1.3 Vaives. Valves up through two 
(2) inches (50 mm) in size shall be brass, 
malleable iron, or steel bodies. Each gate 
valve shall be a full-way type with working 
parts of noncorrosive metal. 

1201.2.1.4 Fittings. 

1 201 .2.1 .4.1 Plain screwed fittings shall 
be brass, bronze, cast iron, galvanized 
or black malleable iron, or galvanized or 
black steel. 

1201.2.1.4.2 Fittings for copper tubing 
shall be wrought copper, wrought 
bronze, or cast brass. 

1201.2.1.4.2.1 IVIechanically Formed 
Tee Fittings. Mechanically extracted 
collars shall be formed in a conti- 
nuous operation consisting of driUing 
a pilot hole and drawing out the tube 
surface to form a collar having a 
height not less than three times the 
thickness of the branch tube wall. 

The branch tube shall be notched 
to conform with the inner curve of 
the run tube and have two dimple/ 



depth stops to er^ure that penetration 
of the branch tube into the collar is of 
sufficient depth for brazing and that 
the branch tube does not obstruct the 
flow in the main line tube. Dimple/ 
depth stops shall be in Une with the 
run of the tube. The second dimple 
shall be 1/4 inch (6.35 mm) above the 
first and shall serve as a visual point 
of inspection. 

All joints shall be brazed in 
accordance with Section 212.0. Soft 
soldered joints shall not be allowed. 

1201.2.1.4.3 Welding fittings shall be 
black steel. 

1201.2.1.4.4 Fittings for asbestos-cement 
shall be cast iron. 

1201.2.1.5 Pipe Joint Compound. Pipe 
joint compound shall be noncorrosive and 
insoluble in the material being carried in 
the pipe. 

1201.2.1.6 Protective Coatings. Protective 
coatings shall be watertight, durable, heat 
resistant, electrically noncbnductive, and 
tightly adherent to the pipe. 

1201.2.1.7 Fluxes. Fluxes for solder, sweat, 
and brazed joints shall be a noncorrosive 
type and suitable for the use intended. 

1201.2.1.8 Insulation. Coverings or 
insulation used on hot water or steam pipes 
shall be of materials suitable for the 
operating temperature of the system. The 
insulation, jackets, and lap-seal adhesives 
shall be tested as a composite product and 
shall have a flame-spread index of not more 
than 25 and a smoke-developed index of not 
more than 50 when tested in accordance 
with Building Code standards. 

1201.2.1.9 Flasliing Material. Flashings 
shall be lead, copper, galvanized iron, or 
other approved materials. 

1201.2.1.10 Gasl<ets. Flange gaskets shall 
be metal, asbestos, or other approved 
materials. 

1201.2.1.11 Hangers and Ancliors. 

Hangers and anchors shall be suitable for 
tiie use intended. 



191 



1201.2 



2007 CALIFORNIA MECHANICAL CODE 



1201.2.1.12 Sleeves. Sleeves shall be of 
steel, cast-iron or wr ought-iron pipe, or tile. 

1201.2.1.13 Standards. All piping, tubing, 
valves, joints, fittings, devices, and materials 
shall be free of defects and comply with 
nationally recognized standards. 

1201.2.1.14 Marking. Materials and devices 
shall be suitably identified. In addition to 
the incised marking required in the 
standards, all hard-drawn copper tubing 
shall be marked in accordance with the 
applicable standard found in Chapter 17. 
Color coding shall be as follows: 

Type L - Blue 

Type K - Green 

Type M- Red 

Type ACR- Blue 

Type DWV- Yellow 

1201.2.2 Fabrication of Joints. Joints shall be 
made by the use of fittings except as otherwise 
permitted in this chapter. 

1201.2.2.1 Screwed Joints. Threads on 
iron pipe size (IPS pipe) shall be standard 
taper pipe threads. All burrs shall be 
removed. Pipe ends shaU be reamed or filed 
out to the full size of bore, and all chips shall 
be removed. 

1201.2.2.2 Solder Joints. Surfaces to be 
joined by soldering shall be cleaned bright 
by manual or mechanical means. The joints 
shall be properly fluxed using a listed 
soldering flux. (See Soldering Fluxes in 
Referenced Standards, Chapter 17, Part II of 
this code). Tubing shall be reamed out to the 
full size of bore. 

1201.2.2.3 Welded Joints. Welding shall be 
performed in accordance with nationally 
recognized standards by certified welders. 

1201.2.2.4 Flanged Joints. Flanged joints 
shall be tightened evenly and provided with 
suitable nuts, bolts, and gaskets. 

1201.2.2.5 Mechanical Joints. Mechanical 
joints shall comply with nationally recog- 
nized standards. 

1201.2.3 Connections. 

1201.2.3.1 Brass and Copper Piping. 

Joints in brass and copper piping shall be 
threaded, brazed, welded, flanged, or 
mechanical type. 

1201.2.3.2 Cast-Iron Piping. Joints in cast- 



iron pipe shall be threaded, flanged, or 
mechanical tjq^e. 

1201.2.3.3 Galvanized Wrought-lron and 
Galvanized Steel Piping. Joints in 
galvanized wrought-iron and galvanized 
steel piping shall be threaded, flanged, or 
mechaiucal type. 

1201.2.3.4 Black Wrought-lron Piping. 

Joints in black wrought-iron piping shall be 
threaded, brazed, welded, flanged, or 
mechanical tjrpe, except that joints built into 
or embedded in concrete or masonry shall 
be welded. 

1201.2.3.5 Black Steel Piping. Joints in 
black steel piping shall be threaded, brazed, 
welded, flanged, or mechanical type. 

1201.2.3.6 Asbestos-Cement Piping. 

Joints in asbestos-cement piping shall be 
mechanical type and suitable for the service 
temperature intended. 

1201.2.3.7 Copper Water Tubing. Joints in 
copper tubing shall be soldered, brazed or - 
flared, except that joints under a building | 
and in or under any concrete slab resting on 
the groimd shall be silver brazed, or equal, 
and fittings shall be of wrought copper. 
Mechanically formed tee fittings are also 
acceptable when brazed and installed in 
accordance with Section 1201.2.1.4. All 
solder joints shall be made with solders 
meeting the standard for solder metal found 
in Chapter 17. However, if steam pressures 
exceed fifteen (15) psig (103 kPa) or water 
pressures exceed thirty (30) psig (206 kPa), 
then 50 percent tin-50 percent lead solder 
shall not be used. Solders and fluxes with a 
lead content which exceeds two-tenths (0.20) 
of 1 percent shall be prohibited in piping 
systems conveying potable water. 

1201.2.3.8 Piping to Tubing. Joints connec- 
ting piping to tubing shall be made with 
adapter fittings connected as required in 
Sections 1201.2.3.1 through 1201.2.3.7. 

1201.2.4 Changes in Direction. Changes in 
direction shaU be made by the appropriate use of 
fittings, except that changes in direction in 
copper tubing may be made with bends having a 
radius not less than six diameters of the tubing, 
provided that such bends are made by the use 
of forming equipment that does not deform or 
reduce appreciably the cross-^sectional area of 
the tubing. 



192 



HYDRONICS 



1201.2 



1201.2.5 Changes in Pipe Sizes. Where different 
sizes of pipe or pipe and fittings are to be connec- 
ted, the proper size increasers or reducer fittings 
shall be used between the two sizes. When the 
branch is at least two sizes smaller than the main, 
weldolets or threadolets may be used in lieu of 
welding tees. Bushings shall not be used. Eccentric 
reducing fittings shall be used wherever necessary 
to provide free draiaage of lines. 

1201.2.6 Hangers and Supports. All piping 
and equipment shall be adequately supported to 
the satisfaction of the Authority Having 
Jurisdiction. Hot-water and steam piping shall 
be supported, anchored, and provided with 
swing joints, expansion loops or joints, or other 
means to avoid excessive strain on piping, 
equipment, or the building structure to the 
satisfaction of the Authority Having Jurisdiction. 

1201.2.6.1 Verticai Piping— Attactiment. 

Vertical piping and tubing shall be secured 
at sufficiently close intervals to keep the 
pipe in alignmient and carry the weight of 
the pipe and contents. 

1201.2.6.2 Horizontai Piping. 

1201.2.6.2.1 Supports. Horizontal 

piping and tubing shall be supported at 
sufficiently close intervals to keep it in 
alignment and prevent excessive 
sagging. 

1201.2.6.2.2 in Ground. Piping and 
tubing in the ground shall be laid on a 
firm bed for its entire length except 
when otherwise approved by the 
Authority Having Jtirisdiction. Asbestos- 
cement piping shall be provided with 
adequate thrust blocking. 

1201 .2.7 instaliation. 

1201.2.7.1 Same iVIaterials Required. All 

piping materials used, except valves and 
similar devices, shall be of a like material, 
except as otherwise acceptable to the 
Authority Having Jurisdiction. 

1201.2.7.2 Wall Tiiickness. 

1201.2.7.2.1 Piping shall be at least 
standard-weight brass or copper. Class 
150 cast iron, standard-weight wrought 
iron, ASTM Schedule 40 steel, or 
suitable asbestos-cement of adequate 
pressure rating. 

1201.2.7.2.2 Tubing shall be at least 
Type K — for condensate return lines; 
Type L — for steam condenser cooling 



water lines, underground water lines, 
and aboveground water lines; Type 
M — for aboveground water lines not 
embedded in concrete or masonry. 

1201.2.7.3 Piping Embedded in Structure. 

Piping shall not be built into or embedded 
in concrete or masonry, except where used 
for radiant panel heating or cooling. Black 
steel pipe, wrought-iron piping, or Type L 
copper tubing may be so embedded. 

1201.2.7.4 Cutting Structure. Structural 
members shall not be seriously weakened or 
impaired by cutting or notching. 

1201.2.7.5 Providing for Expansion, 
Contraction, and Settling. Piping shall be 
installed so that piping, connections, and 
equipment shall not be subjected to 
excessive strains or stresses, and provisions 
shall be made for expansion, contraction, 
shrinkage, and structural settlement. 

1201.2.7.6 Circulation. Piping shall provide 
adequate circulation. Piping shall be graded so 
that all gases can move in the direction of the 
water flow to a vented section of the system. 
When sectioris of a piping system cannot be 
installed with the required grade, such 
sections shall be provided with automatic or 
manual air vents whose discharge is piped to 
an approved location. Steam traps shall be 
provided where reqiured. 

1201.2.7.7 Underground Piping. 

1201.2.7.7.1 Cinders and Other 
Corrosive Material Fills. All piping 
passing through or under cinders or 
other corrosive fill materials shall be 
suitably protected from corrosion. 

Exception: Where a soil analysis by 
an acceptable testing laboratory 
shows the soil to be free of 
materials that may corrode the pipe 
to be installed, the requirements for 
protective coatings may be waived. 

1201.2.7.7.2 Beneath Buildings. Piping 
installed within a building and in, or 
under, a concrete floor slab resting on 
the ground shall be installed as follows: 

Ferrous Piping. Ferrous piping shall 
be galvaruzed and covered with an 
approved protective coating. 

Copper Tubing. Copper tubing 
shall be installed without joints, 
where possible. 



193 



1201.2 



2007 CALIFORNIA MECHANICAL CODE 



Asbestos-Cement. Asbestos-cement 
pipe shall not be installed beneath 
any btdlding. 

1201.2.7.7.3 Outside of Buildings. 

Black Wrought Iron and Black Steel. 

Black wrought-iron and black steel 
piping shall be protected against corro- 
sion by an approved pipe wrapping. 

Asbestos-Cement. Asbestos-cement 
piping shall be installed in accordance 
with the manufacturer's recommendations, 
but shall not be installed within two (2) 
feet (610 mm) of any btdlding. 

1201.2.7.7.4 Under Walls or Founda- 
tions. Piping passing under walls or 
foundations shall be protected from 
breakage. 

1201.2.7.7.5 Openings into Buildings. 

Voids around piping passing through 
concrete or masonry floors or walls 
shall be appropriately sealed at the 
opening into the building. Sleeves shall 
be provided at such openings. 

1201.2.7.8 Aboveground Piping. 

1201.2.7.8.1 Sleeves. Sleeves shall be 
provided to protect all piping through 
concrete and masonry walls. 

1201.2.7.8.2 Insulation. The temperature 
of surfaces within normal reach of btuld- 
ing occupants shall not exceed 140°F 
(60°C) unless they are protected by 
suitable insulation. Where sleeves are 
installed, any insulation shall continue 
full-sized through them. 

1201.2.7.8.3 Lining. Combustible 
portions of unventilated spaces that 
contain piping or devices whose outside 
temperature, including insulation, 
exceeds 140°F (60°C), shall be lined with 
No. 24 gauge (0.021 inch) (0.53 mm) 
steel, or 1/4 inch thick (6.4 mm) 
insulating millboard. 

1201.2.7.8.4 Clearance. There shall be 
at least one (1) inch (25.4 mm) clearance 
from the structure aroiind steam pipes. 

1201.2.7.8.5 Exposed Piping. Exposed 
piping subject to excessive corrosion, 
erosion, or mechanical damage shall be 
suitably protected. 

1201.2.7.8.6 Asbestos-Cement Piping. 

Asbestos-cement piping shall not be 
installed within any building. 



1201.2.7.8.7 Roof and Wall Openings. 

Joints at the roof around pipes or 
appurtenances shall be made watertight 
by the use of approved flashings or 
flashing material. Exterior wall openings 
shall be made watertight. 

1201.2.7.8.8 Drainage. Means shall be 
provided to drain all piping. 

1201.2.7.8.9 Freezing. Where required, 
piping outside of a building or in an 
exterior wall shall be protected from 
freezing. 

1201.2.7.9 Trenches and Tunnels. 

1201.2.7.9.1 Protection of Structure. 

Trenches deeper than the footings of a 
building or structure and paralleling the 
same shaU be at least 45 degrees there- -. 
from, or approved per Section 105.0. | 

1201.2.7.9.2 IVIechanical Equipment. 

Use of mechanical excavating equipment 
is prohibited within two (2) feet (610 nmi) 
of existing piping or appurtenances. 

1201.2.7.9.3 Tunneling and Driving. 

Timnels shall, before backfilling, have a 
clear height of two (2) feet (609.6 mm) 
above the pipe and shall be limited in 
length to one-half the depth of the 
trench, with a maximum length of eight 
(8) feet (2,438.4 mm). When pipes are 
driven, the drive pipe shall be at least 
one size larger than the pipe to be laid. 

1201.2.7.9.4 Backfilling. Excavations 
shall be completely backfilled as soon 
after inspection as practicable. Adequate 
precaution shall be taken to ensure 
proper compaction of backfill around 
piping without damage to such piping. 
Trenches shall be backfilled in thin 
layers to twelve (12) inches (304.8 nun) 
above the top of the piping with clean 
earth that shall not contain stones, 
boulders, cinderfill, or other materials 
that wotild damage, break the piping, or 
cause corrosive action. Mechanical 
devices, such as bulldozers, graders, 
etc., may then be used to complete 
backfill to grade. Fill shall be properly 
compacted. Suitable precautions shall 
be taken to ensure permanent stability 
for pipe laid in filled or made groxmd. 

1201.2.8 Pressure Testing. 

1201.2.8.1 Responsibility. The equip- 
ment, material, and labor necessary for 



194 



HYDRONICS 



1201.2-1201.3 



inspection or test shall be furnished by 
the person to whom the permit is issued 
or by whom inspection is requested. 

1201.2.8.2 Media. The piping shall be 
tested with water. 

1201.2.8.3 Pressure Test. Piping shall 
be tested with a hydrostatic pressure of 
not less than 100 psig (689 kPa), but at 
least fifty (50) psig (345 kPa) greater 
than operating pressure. This pressure 
shall be maintained for at least thirty 
(30) minutes. Required tests shall be 
conducted by the owner or contractor in 
the presence of an authorized inspector. 
The piping being tested shall remain 
exposed to the inspector and shall not 
leak during the test. 

1201.2.8.4 Moved Structures. Piping 
systems of a building and parts thereof 
that are moved from one foundation to 
another shall be completely tested as 
prescribed elsewhere in this section for 
new work, except that walls or floors 
need not be removed during such test 
when equivalent means of inspection 
are provided. 

1201.2.8.5 Test Waived. No test or 
inspection shall be required where a 
system, or part thereof, is set up for ex- 
hibition purposes and has no cormec- 
tion with a water system. 

1201.2.8.6 Exceptions. In cases where 
it would be impractical to provide the 
aforementioned tests, or for minor 
installations and repairs, the Authority 
Having Jurisdiction shall have the 
authority to make such inspection as it 
deems necessary. 

1201.3 Those portions of fhe hot water piping systems 
in which the continuous pressure-temperature 
relationship does not exceed the following may be 
constructed of polybutylene pipe or tubing of SDR-11 
conforming to specification ASTM D 3309. 

Temperature Pressure 

°F (°C) psi (kPa) 

73 (23) 200 (1379) 

180 (82) 100 (689) 

200 (93) 8 (55) 

: jpolybutylene also may be used for applications 
requiring up to one (l).year total exposure at 



conditions of 210°F (99°C), 150 psi (1027 kPa), typical 
conditions for temperature and pressure-relief valve 
discharge lines in heating systems. 

1201.3.1 Materials and Construction. 

1201.3.1.1 PB Pipe and Tubing. Pipe shall be 
IPS or copper tube size polybutylene, both 
SDR-11 conforming to ASTM D 3309. 

1201.3.1.2 Fittings. Fittings shall be of 
polybutylene or metal. 

1201.3.1.3 Insulation. Coverings and 
insulation used on hot water pipes shall be 
of materials suitable for the operating 
temperature of the system. The insulation, 
jackets, and lap-seal adhesives shall be 
tested as a composite product and shall have 
a flame-spread index of not more than 25 
and a smoke-developed index of not more 
than 50 when tested in accordance with 
Building Code standards. 

1201.3.1.4 Gaskets. Flanged PB systems 
may be kistaUed without gaskets. 

1201.3.1.5 Hangers, Sleeves, and Anchors. 

Hangers, sleeves, and anchors shall be 
suitable for the use intended as recom- 
mended by the manufacturers' installation 
instructions. 

1201.3.1.6 Standards. All piping, tubing, 
valves, joints, fittings, devices, and materials 
shall be free of defects and comply with 
nationally recognized standards approved 
by the Authority Having Jurisdiction. 

1201.3.1.7 Marldng. Materials and devices 
shall be suitably identified. 

1201.3.2 Fabrication of Joints. Joints shall be 
made by one or more of the following methods: 

1201.3.2.1 Socket Fusion. Polybutylene 
socket fittings may be heat-fused to the pipe. 

1201.3.2.2 Crimp/Insert Fittings. Insert 
fittings of metal with crimp rings of 
aluminum or copper may be used. 

1201.3.2.3 Compression Fittings. MetalUc 
or polybutylene fittings utilizing com- 
pression seals are acceptable. 

1201.3.2.4 Transition Fittings. Connections 
to other piping materials shall be made by 
approved types of special transition fittings. 

1201.3.3 Changes in Direction. Changes in 
direction shall be made by the appropriate use of 
fittings or with pipe bends having a radius of 
not less than ten (10) diameters of the pipe. No 
forming equipment or heating is required. 



195 



1201.3-1201.4 



2007 CALIFORNIA MECHANICAL CODE 



1201.3.4 Hangers and Support:. Piping and 
equipment shall be adequately supported and 
secured. Hot water piping shall be provided 
with swing joints, or expansion loops or joints, 
or utilize the pipe's flexibility to avoid strain on 
piping, equipment, or the building structure. 

1201.3.5 Installation Details. 

1201.3.5.1 Piping Embedded in Structure. 

Piping shaU not be built into or embedded 
in concrete or masonry, except where used 
for radiant panel heating or cooUng. See Part 
n of this chapter. 

1201.3.5.2 Cutting Structure. Structural 
members shall not be seriously weakened or 
impaired by cutting or notching. 

1201.3.5.3 Under Walls or Foundations. All 

piping passing under load-bearing foun- 
dations shall be protected by sleeving. 

1201.3.5.4 Openings into Buildings. Voids 
around piping passing through concrete or 
masonry floors or walls shall be appro- 
priately sealed at the opening into the 
building. Sleeves shall be provided at such 
openings. 

1201.3.5.5 Aboveground Piping. 

1201.3.5.5.1 Sleeves. Sleeves shall be 
installed where piping passes through 
masonry, concrete, or any fire separation. 

1201.3.5.5.2 Insulation. The temperature 
of surfaces within normal reach of 
building occupants shall not exceed 
140°F (60°C) unless they are protected 
by suitable insulation. Where sleeves 
are installed, any insulation shall 
continue full-sized through them. 

1201.3.5.6 Belowground Piping. 

1201.3.5.6.1 Protection of Structure. 

All trenches deeper than the footings of 
any building or structure and paralle- 
ling the same shall be at least 45 degrees 
therefrom, unless otherwise permitted 
by the Authority Having Jurisdiction. 

1201.3.5.6.2 Mechanical Equipment. 

Use of mechanical excavating equipment 
is prohibited within two (2) feet (609.6 
mm) of existing piping or appurtenances. 

1201.3.5.6.3 Boring and Pulling. 

Boring pipe shall be at least one size 
larger than the pipe to be laid. Pulling 
force shall not exceed the tensile yield 
strength of the pipe. 

1201.3.5.6.4 Baclcfilling. All excavations 



shall be completely backfilled as soon 
after inspection as practicable. Adequate 
precaution shall be taken to ensure 
proper compaction of the backfill 
around piping without damage to such 
piping. Trenches shall be backfilled in 
thin layers to twelve (12) inches (304.8 
mm) above the top of the piping with 
clean earth that shall not contain stones, 
boulders, dnderfiU, or other materials that 
would damage or break the piping. 
Mechanical devices, such as bulldozers, 
graders, etc., may then be used to 
complete backfill to grade. Fill shall be 
properly compacted. Suitable precautions 
shall be taken to ensure pemnanent stability 
for pipe laid in filled or made ground. 

1201.3.5.6.5 Pipe or Tube Under 
Concrete. Pipe or tubing installed 
beneath footings or slabs shall be in 
continuous lengths or with fused joints. 

1201.3.6 Pressure Testing. 

1201.3.6.1 Responsibility. The equip- 
ment, material, and labor necessary for 
inspection or test shall be furnished by 
the person to whom the permit is issued 
or by whom inspection is requested. 

1201.3.6.2 Media. The piping shall be 
tested with water. 

1201.3.6.3 Pressure Test. Piping shall 
be tested with a hydrostatic pressure of 
not less than 100 psig (689 kPa) or 1.5 
times the system design operating 
pressure. The pressure shall be main- 
tained for thirty (30) minutes, at that 
time the indicated pressure may have 
decreased due to the initial expansion 
of the pipe. After thirty (30) minutes, 
adjust the system to the required 
pressure and visually inspect for leaks. 
Required tests shall be conducted by 
the owner or contractor in the presence 
of an authorized inspector. The piping 
being tested shall remain exposed to 
the inspector and shall not leak during 
the test. 

1201.4 Those portions of the hot water piping 
systems in which the continuous pressure- 
temperature relationship does not exceed the 
following may be constructed of cross-linked 
polyethylene (PEX) tubing of SDR-9 conforming to 
specifications ASTM F876 and F877. 



196 



HYDRONICS 






Temperature 


Pressure 


op 


(°C) 


psi (kPa) 


73 


(23) 


160 (1103) 


180 


(82) 


100 (689) 


200 


(93) 


80 (550) 



1201.4.1 Materials and Construction. 

1201.4.1.1 PEX Tubing. Tubing shall be 
copper tube size, SDR-9 cross-linked 
polyethylene conforming to ASTM F876. 
PEX tubing and fittings shall be installed in 
accordance with the manufacturers' recom- 
mended installation instructions. 

1201.4.1.2 Fittings. Fittings shall be 
manufactured and tested in accordance with 
the nationally recognized standards. 

1201.4.1.3 Insulation. Coverings and insu- 
lation used for hot water pipes shall be of 
material suitable for the operating tempe- 
rature of the system. The insulation, jackets, 
and lap-seal adhesives, including pipe 
coverings and linings, shall have a flame- 
spread index not greater than 25 and a 
smoke-developed index not greater than 50 
when tested in accordance with NFPA 255, 
Method of Test of Burning Characteristics of 
Building Materials; or in accordance with 
ASTM E 84, Surface Burning Characteristics 
of Building Materials; or in accordance with 
the provisions of UL 723, Test for Surface 
Burning Characteristics of Building 
Materials. The specimen preparation and 
mounting procedures of ASTM E 2231, 
Specimen Preparation and Moimting of Pipe 
and Duct Insulation Materials to Assess 
Surface Burning Characteristics shall be 
used. Alternately, materials used for pipe 
coverings and insulation (including the 
insulation, jacket, and lap-seal adhesives) 
shall have a maximum peak heat release rate 
of 300 kW, a maximum total heat release of 
50MJ, a maximum total smoke release of 500 
m^ and shall not generate flames that extend 
one (1) foot (0.3m) or more above the top of 
the vertical portion of the apparatus at any 
time during the test when tested in 
accordance with NFPA 274, Standard Test 
Method to Evaluate Fire Performance 
Characteristics of Pipe Insidation. Insulation 
coverings and linings shall not flame, glow, 
smolder, or smoke when tested in 
accordance with ASTM C 411, Hot-Surface 



1201.4-1201.5 

Performance of High Temperature Thermal 
Insulation, at the temperature to which they 
are exposed in service. In no case shall the 
test temperahire be below 250°F (121°C). 

1201.4.1.4 Hangers, Sleeves, and Anchors. 

Hangers, sleeves, and anchors shall be 
suitable for the use intended as recom- 
mended by the manufacturers' installation 
instructions. 

1201.4.1.5 Standards. AH piping, tubing, 
and fitting materials shall be free of defects 
and comply with nationally recognized 
standards approved by the Authority 
Having Jurisdiction. 

1201.4.1.6 Marl<ing. Materials and devices 
shall be suitably identified. 

1201.4.2 Fabrication of Joints. All joining 
methods shall meet the performance requirements 
set forth in ASTM F877. Joints shall be made by 
one or more of the following methods: 

1201.4.2-1 Crimp/Insert Fittings. Insert 
fittings of metal with crimp rings of copper 
may be used. 

1201.4.2.2 Compression Fittings. Metallic 
fittings utilizing compression seals are 
acceptable. 

1201.4.2.3 Cold Expansion Fittings. Cold 
expansion fittings utilizing a PEX rein- 
forcing ring or metal compression sleeve 
may be used. 

1201.4.2.4 Transition Fittings. Connections 
to other piping materials shall be made of 
approved types of special transition fittings. 

1201.4.3 Changes in Direction. Changes in 
direction shall be made by the appropriate use of 
fittings or with pipe bends having a radius of 
not less than six times the outside diameter of 
the tubing. No forming equipment or heating is 
required. 

1201.5 Those portions of the hot water piping 
systems in which the continuous pressure 
temperature relationship does not exceed the 
following shall be permitted to be constructed of 
cross-linked polyethylene/aluminum/cross-linked 
polyethylene (PEX-AL-PEX) piping conforming to 
specification ASTM F1281. 



197 



1201.5-1206.0 



2007 CALIFORNIA MECHANICAL CODE 



Temperature 
r (C°) 

73 (23) 
180 (82) 
200 (93) 



Pressure 
psi (kPa) 

200 (1,380) 
125 (862) 
100 (690) 



1201.5.1 Materials and Construction. 

1201.5.1.1. PEX-AL-PEX. Piping shall be 
crosslinked polyethylene/alumiiitim/cross- 
Unked polyethylene conforniing to ASTM F 
1281. PEX-AL-PEX piping and fittings shall 
be installed in accordance with the manufac- 
turers' recommended installation iastructions. 

1201.5.1.2 Fittings. Fittings shall be manu- 
factured and tested in accordance with the 
nationally recognized standards. 

1201.5.1.3 Insuiation. Coverings and insu- 
lation used for hot water pipes shall be of 
materials suitable for the operating 
temperature of the system. The insulation, 
jackets, and lap-seal adhesives shall be 
tested as a composite developed rating of 
not more than 50 when tested in accordance 
with Building Code standards. 

1201.5.1.4 l-langers, Sleeves, and Anciiors. 

Hangers, sleeves, and anchors shall be 
suitable for the use intended as recom- 
mended by the manufacturers' installation 
instructions. 

1201.5.1.5 Standards. All piping and 
fitting materials shall be free of defects and 
comply with nationally recognized standards 
in Chapter 17. 

1201.5.1.6 Maridngs. Materials and devices 
shall be suitably identified. 

1201.5.2 Fabrication of Joints. All joining 
methods shall meet the performance requirements 
set forth in ASTM F1281. Joints shall be made by 
one or more of the following methods: 

1201.5.2.1 Crimp/Insert Fittings. Insert 
fittings of metal with crimp rings of copper 
may be used. 

1201.5.2.2 IVlechanicai Compression 
Fittings. Metallic fittings utilizing a split 
ring and compression nut are acceptable. 

1201.5.2.3 Transition Fittings. Connections 
to other piping materials shall be made of 
approved tj^es of special transition fittings. 

1201.5.3 Changes in Direction. Changes in 
direction shall be made by fittings or with pipe 



bends having a radius of not less than five (5) 
times the outside diameter of the piping. No 
fommig eqtdpment or heating is reqxiired. 

Part II - Hydronic Panel i-leating Systems 

1202.0 Scope. 

The purpose of this part is to establish and provide 
minimum standards for the protection of public 
health, welfare, and property by regulating and 
controlling the design and installation of panel 
heating systems. 

1203.0 Installation. 

1203.1 Panel systems shall be designed and installed 
in accordance with installation standards incorporated 
in Chapter 17 Panel Heating, and the requirements 
of this code. 

1 203.2 Piping to be embedded in concrete shall be 
pressure-tested prior to pouring concrete. During 
pouring, the pipe shall be m.aintained at the 
proposed operating presstire. 

1204.0 Piping iVIaterials. 

1204.1 Panel(s). Piping for heating panels shall be 
standard-weight steel pipe. Type L copper tubing, or 
approved plastic pipe or tubing rated at 100 psi (689 
kPa)atl80°F(82°C). 

1204.2 Hot-Water Supply Lines. Piping for hot-water 
supply lines shall be installed according to the 
requirements in Chapter 10. 

1205.0 Piping Joints. 

Joints of pipe or tubing forming the panel that are 
embedded in a portion of the btiilding, for example, 
concrete or plaster, shall be in accordance with the 
following: 

1205.1 Steel pipe welded with electrical arc or 
oxygen/ acetylene method. 

1205.2 Copper tubing joined with brazing alloys 
having a melting point above 1,000°F (538°C). 

1206.0 Heat Sources. 

Heat sources for generating hot water for use in 
hydronic panel radiant heating systems shaU include 
conventional fossil fuel, hot water boilers, electrical- 
resistance heated boilers, air/water or water /water 
heat piimps, or solar heat collector systems. The latter 
system may include booster or backup heating units. 

Systems shall be protected by pressure- 
temperature reUef valves as outliaed in this code. 



198 



HYDRONICS 1207.0 

1207.0 Testing. 

Approved piping or tubing installed as a portion of a 
radiant panel system that will be embedded in the 
walls, floors, or ceUings of the buUding it is designed 
to heat shall be tested for leaks by the hydrostatic 
test method by applying at least 100 psi (689 kPa) 
water pressure or 1.5 times the operating pressure, 
whichever is greater. 

For metal piping, a pressure gauge shall be 
connected to the piping, and after the pressure has 
been raised, the hydrostatic pressure connection 
shall be discontinued and the systems under 
pressure shall remain at the test pressure for a 
sufficient period of time to determine whether any 
leaks exist in the system. Leaks shall be indicated by 
the pressure drop on the gauge. The minimum test 
period shall be thirty (30) minutes. 

For flexible plastic piping, the test pressure shall 
be applied for a period of thirty (30) minutes. During 
this time, the system shall be maintained at the test 
pressure by the periodic addition of makeup water 
to compensate for the initial stretching of the pipe. 
The system shall then be visually inspected for 
tightness. 

Tests for tightness of radiant piping systems 
shall be witnessed by the Authority Having 
Jurisdiction. 



199 



2007 CALIFORNIA MECHANICAL CODE 



200 



CHAPTER 13 



Note: 



FUEL GAS PIPING 
Portions of this chiapter have been reproduced in their entirety from NFPA 54-2002. (ANSI Z223.1) 



Part I - Fuel Piping 



1301.0 Scope. 

(A) Coverage of piping systems shall extend from 
the point of delivery to the connections with 
each gas utilization device. For other than 
undiluted liquefied petroleum gas systems, the 
point of delivery shall be considered the outlet 
of the service meter assembly or the outlet of the 
service regulator or service shutoff valve where 
no meter is provided. For undiluted liquefied 
petroleum gas systems, the point of delivery 
shall be considered the outlet of the final 
pressure regulator, exclusive of the line gas 
regulators, in the system. [NFPA 54:1. 1.1. 1(A)] 

(B) Piping systems requirements shall include 
design, materials, components, fabrications, 
assembly, installation, testing, inspection, 
operation, and maintenance. [NFPA 54:1.1. 1.1(C)] 

(C) This code shall not apply to the following 
(reference standards for some of which appear in 
Chapter 17 [NFPA 54:1.1.2]): 

(1) Portable LP-Gas equipment of all types that 
is not connected to a fixed fuel piping system. 

(2) Installation of farm equipment, such as 
brooders, dehydrators, dryers, and irrigation 
equipment. 

(3) Raw material (feedstock) applications except 
for piping to special atmosphere generators. 

(4) Oxygen-fuel gas cutting and welding systems. 

(5) Industrial gas applications using such gases 
as acetylene and acetylenic compounds, 
hydrogen, ammonia, carbon monoxide, 
oxygen, and nitrogen. 

(6) Petroleum refineries, pipeline compressor or 
pumping stations, loading terminals, 
compounding plants, refinery tank farms, 
and natural gas processing plants. 

(7) Large integrated chemical plants or portions 
of such plants where flammable or combustible 
liquids or gases are produced by chemical 
reactions or used in chemical reactions. 

(8) LP-Gas installations at utility gas plants. 

(9) Liquefied natural gas (LNG) installations. 

(10) Fuel-gas piping in power and atomic energy 
plants. 



(11) Proprietary items of equipment, apparatus, 
or instruments, such as gas-generating sets, 
compressors, and calorimeters. 

(12) LP-Gas equipment for vaporization, gas 
mixing, and gas manufacturing. 

(13) LP-Gas piping for buildings under 
construction or renovations that are not to 
become part of the permanent building 
piping system — that is, temporary fixed 
piping for building heat. 

(14) Installation of LP-Gas systems for railroad 
switch heating. 

(15) Installation of LP-Gas and compressed 
natural gas systems on vehicles. 

(16) Gas piping, meters, gas-pressure regulators, 
and other appurtenances used by the serving 
gas supplier in the distribution of gas, other 
than undiluted LP-Gas. [NFPA 54:1.1.1.2] 

1302.0 General. 

The regulations of this chapter shall govern the 
installation of all fuel-gas piping in or in connection 
with any building or structure or within the property 
lines of any premises up to 5 psi, other than service 
pipe. Fuel-oil piping systems shall be installed in 
accordance with NFPA 31. 

Exception: Gas piping, meters, gas pressure 
regulators, and other appurtenances used by the 
serving gas supplier in the distribution of gas, 
other than undiluted LP-Gas [NFPA 54: 1.1.1.2] 

1303.0 Definitions. 

For the purposes of this code, these definitions shall 
apply to this chapter. Certain terms, phrases, words, 
and their derivatives shall be interpreted as set forth 
in this section, provided, however, that whenever the 
words "gas meters" appear, they shall be construed to 
also mean valves and those devices required for the 
regulation of pressure and the measurement of 
natural gas being dispensed for any building, 
structure, or premises. 

1303.1 Appliance Fuel Connector. An assembly of 
listed semirigid or flexible tubing and fittings to 
carry fuel between a fuel-piping outlet and a fuel- 
burning appliance. 

1303.2 Fuel Gas. Natural, manufactured, liquefied 
petroleum, or a mixture of these. 



201 



1303.3-1305.2 



2007 CALIFORNIA MECHANICAL CODE 



1303.3 Gas Piping. Any installation of pipe, valves, 
or fittings that is used to convey fuel gas, installed on 
any premises or in any building, but shall not include: 

(1) Any portion of the service piping. 

(2) Any approved piping connection six (6) feet 
(1,829 mm) dr less in length between an existing 
gas outlet and a gas appliance in the same room 
with the outlet. 

1303.4 Gas Piping System. Any arrangement of 
gas piping supplied by one (1) meter and each 
arrangement of gas piping serving a building, 
structure, or premises, whether individually metered 
or not. 

1303.5 Liquefied Petroleum Gas (LP-Gas) 
Facilities. Liquefied petroleum gas facilities are 
tanks, containers, container valves, regulating 
equipment, meters, and /or appurtenances for the 
storage and supply of liquefied petroleum gas for any 
building, structure, or premises. 

1303.6 Provision for Location of Point of Delivery. 

The location of the point of delivery shall be 
acceptable to the serving gas supplier. [NFPA 54:5.2] 

1303.7 Quick-Disconnect Device. A hand-operated 
device that provides a means for coruiecting and 
disconnecting an appliance or an appliance connector 
to a gas supply and that is equipped with an 
automatic means to shut off the gas supply when the 
device is disconnected. 

1303.8 Service Piping. The piping and equipment 
between the street gas main and the gas piping 
system inlet that is installed by, and is under the 
control and maintenance of, the serving gas suppUer. 

1303.9 Transition Gas Riser. Any listed or approved 
section or sections of pipe and fittings used to 
convey fuel gas and installed in a gas piping system 
for the purpose of providing a transition from below- 
ground to aboveground. 

1304.0 Inspection. 

1304.1 Upon completion of the installation, alteration, 
or repair of any gas piping, and prior to the use 
thereof, the Authority Having Jurisdiction shall be 
notified that such gas piping is ready for inspection. 

1304.2 All excavations required for the installation 
of imdergroimd piping shall be kept open until such 
time as the piping has been inspected and approved. 
If any such piping is covered or concealed before 
such approval, it shall be exposed upon the direction 
of the Authority Having Jurisdiction. 

1304.3 The Authority Having Jurisdiction shall 
make the following inspections and shall either 
approve that portion of the work as completed, or 
shall notify the permit holder wherein the same fails 
to comply with this code. 



1304.3.1 Rough Piping Inspection. This 
inspection shall be made after all gas piping 
authorized by the permit has been installed, 
before any such piping has been covered or 
concealed, or before any fixture or appliance has 
been attached thereto. This inspection shall 
include a determination that the gas piping size, 
material, and installation meet the requirements 
of this code. 

1304.3.2 Final Piping Inspection. This 
inspection shall be made after all piping 
authorized by the permit has been installed and 
after all portions thereof that are to be covered or 
concealed are so concealed and before any 
fixtures, appliance, or shutoff valve has been 
attached thereto. This inspection shall be in 
accordance with Section 1314.1. Test gauges 
used in conducting tests shall comply with 
Section 319.0, Test Gauges from the Uniform 
Plumbing Code: 

319.0 Test Gauges. Tests required by this code, 
that are performed utilizing dial gauges, shall be 
limited to gauges having the following pressure 
graduations or incrementations. 

319.1 Required pressure tests of ten (10) psi (69 
kPa) or less shall be performed with gauges of 
1/10 pound (0.7 kPa) incrementation or less. 

319.2 Required pressure tests exceeding ten (10) 
pounds (69 kPa) but less than one hundred (100) 
psi (689 kPa) shall be performed with gauges of 
one (1) psi (6.9 kPa) incrementation or less. 

319.3 Required pressure tests exceeding one 
hundred (100) psi (689 kPa) shall be performed 
with gauges incremented for two (2) percent or 
less of the required test pressure. 

319.4 Test gauges shall have a pressure range 
not greater than twice the test pressure applied. 

1 304.4 In cases where the work authorized by the 
permit consists of a minor installation of additional 
piping to piping already connected to a gas meter, 
the foregoing inspections may be waived at the 
discretion of the Authority Having Jurisdiction. In 
this event, the Authority Having Jurisdiction shall 
make such inspection as deemed advisable in order 
to be assured that the work has been performed in 
accordance with the intent of this code. 

1305.0 Certificate of Inspection. 

1 305.1 If, upon final piping inspection, the installation 
is found to comply with the provisions of this code, a 
certificate of inspection may be issued by the 
Authority Having Jurisdiction. 

1305.2 A copy of the certificate of such final piping 
inspection shall be issued to the serving gas supplier 
suppl5nng gas to the premises. 



202 



FUEL GAS PIPING 



1305.3-1309.4 



1305.3 It shall be unlawful for any serving gas 
supplier or person furnishing gas to turn on, or cause 
to be turned on, any fuel gas or any gas meter or 
meters until such certificate of final inspection, as 
herein provided, has been issued. 

1306.0 Authority to Render Gas Service. 

1306.1 It shall be unlawful for any person, firm, or 
corporation, excepting an authorized agent or 
employee of a person, firm, or corporation engaged 
in the business of furnishing or supplying gas and 
whose service pipes supply or connect with the 
particular premises, to turn on or reconnect gas 
service in or on any premises where and when gas 
service is, at the time, not being rendered. 

1 306.2 It shall be unlawful to turn on or connect gas 
in or on any premises unless all outlets are properly 
and securely connected to gas appliances or capped 
or plugged with screw joint fittings. 

1307.0 Authority to Disconnect. 

1307.1 The Authority Having Jurisdiction or the 
serving gas supplier is hereby authorized to 
disconnect any gas piping or appliance, or both, that 
shall be found not to conform to the requirements of 
this code or that may be found defective and in such 
condition as to endanger life or property. 

1307.2 Where such disconnection has been made, a 
notice shall be attached to such gas piping or 
appliance, or both, that shall state the same has been 
disconnected, together with the reasons therefor. 

1307.3 It shall be unlawful to remove or disconnect 
any gas piping or gas appliance without capping or 
plugging with a screw joint fitting the outlet from 
which said pipe or appliance was removed. All 
outlets to which gas appliances are not connected 
shall be left capped gastight on any piping system 
that has been installed, altered, or repaired. 

Exception: When an approved listed quick- 
disconnect device is used. 

1308.0 Temporary Use of Gas. 

Where temporary use of gas is desired and the 
Authority Having Jurisdiction deems the use 
necessary, a permit may be issued for such use for a 
period of time not to exceed that designated by the 
Authority Having Jurisdiction, provided that such gas 
piping system otherwise conforms to the requirements 
of this code regarding material, sizing, and safety. 



1309.0 Gas Piping System Design, iVIaterials, and 
Components. 

1309.1 Piping Plan. 

1309.1.1 Installation of Piping System. Where 
j required by the Authority Having Jurisdiction, a 



piping sketch or plan shall be prepared before 
proceeding with the installation. This plan shall 
show the proposed location of piping, the size of 
different branches, the various load demands, 
and the location of the point of delivery. 

1309.1.2 Addition to Existing System. When 
additional gas utilization equipment is being 
cormected to a gas piping system, the existing 
piping shall be checked to determine whether it 
has adequate capacity (see Section 1309.4.3). If 
inadequate, the existing system shall be enlarged 
as required, or separate gas piping of adequate 
capacity shall be provided. 

1309.2 Provision for Location of Point of 
Delivery. The location of the point of delivery shall 
be acceptable to the serving gas supplier. 

1309.3 Interconnections Between Gas Piping 
Systems. 

1309.3.1 Interconnections Supplying 
Separate Users. Where two or more meters, or 
two or more service regulators where meters are 
not provided, are located on the same premises 
and supply separate users, the gas piping 
systems shall not be interconnected on the outlet 
side of the meters or service regulators. 

1309.3.2 Interconnections for Standby Fuels. 

Where a supplementary gas for standby use is 
connected downstream from a meter or a service 
regulator where a meter is not provided, a device 
to prevent backflow shall be installed. A three- 
way valve installed to admit the standby supply 
and at the same time shut off the regular supply 
shall be permitted to be used for this piupose. 

1309.4 Sizing of Gas Piping Systems. 

1309.4.1 General Considerations. Gas piping 
systems shall be of such size and so installed as 
to provide a supply of gas sufficient to meet the 
maximum demand without undue loss of 
pressure between the point of delivery and the 
gas utilization equipment. 

1309.4.2 Maximum Gas Demand. The volume 
of gas to be provided (in cubic feet per hour) 
shall be determined directly from the 
manufacturer's input ratings of the gas 
utilization equipment served. Where the input 
rating is not indicated, the gas supplier, the 
equipment manufacturer, or a qualified agency 
shall be contacted, or the rating from Table 13-1 
shall be used for estimating the volume of gas to 
be supplied. The total connected hourly load 
shall be used as the basis for pipe sizing, 
assuming all equipment is operating at full 
capacity simultaneously. 



203 



Table 13-1 -1309.5 



2007 CALIFORNIA MECHANICAL CODE 



Exception: Sizing shall be permitted to be 
based upon established load diversity 
factors. 

Table 13-1 

Approximate Gas Input for Typical Appliances 



Appliance 



Input 

Btu/h (approx.) 



Space Heating Units 

Warm air furnace 

Single family 100,000 

Multifamily, per urut 60,000 

Hydronic boiler 

Single family 100,000 

Multifamily, per unit 60,000 

Space and Water Heating Units 

Hydroruc boiler 

Single family 120,000 

Multifamily, per unit 75,000 

Water Heating Appliances 

Water heater, automatic storage 

30 to 40 gal tank 35,000 

Water heater, automatic storage 

50 gal tank 50,000 

Water heater, automatic instantaneous 

Capacity at 2 gal/minute 142,800 

Capacity at 4 gal/minute 285,000 

Capacity at 6 gal/minute 428,400 

Water heater, domestic. 

Circulating or side-arm 35,000 

Cooking Appliances 

Range, free standing, domestic 65,000 

Built-in oven or broiler unit, domestic 25,000 
Built-in top xmit, domestic 40,000 

Other Appliances 

Refrigerator 3,000 

Clothes dryer. Type 1 (domestic) 35,000 
Gas fireplace, direct vent 40,000 
Gas log 80,000 
Barbecue 40,000 
Gas light 2,500 

Note: For SI units: 1 Btu per hour = 0.293 W. 

[NFPA 54:Table 5.4.2.1] 



1309.4.3 Sizing iUlethods. Gas piping shall be 
sized in accordance with one of the following: 

(1) Pipe sizing tables or sizing equations in this 
chapter. 

(2) Other approved engineering methods 
acceptable to the Authority Having Jurisdiction. 

(3) Sizing tables included in a listed piping 
system mantif acturer's installation instructions. 

1309.4.4 Allowable Pressure Drop. The design 
pressure loss in any piping system under 
maximum probable flow conditions, from the 
point of delivery to the iiilet cormection of the 
gas utilization equipment, shall be such that the 
supply pressure at the equipment is greater than 
the minimum pressure required for proper 
equipment operation. [NFPA 54:5.4.4] 

1309.5 Acceptable Piping IVIaterials and Joining 
lUlethods. 

1309.5.1 General 

1309.5.1.1 Materials. Materials used for 
piping systems shall comply with the 
requirements of this chapter or shall be 
acceptable to the Authority Having 
Jurisdiction. [NFPA 54:5.6.1.1] 

1309.5.1.2 Used Materials. Pipe, fittings, 
valves, or other materials shall not be used 
again unless they are free of foreign 
materials and have been ascertained to be 
adequate for the service intended. [NFPA 
54:5.6.1.2] 

1309.5.1.3 Other Materials. Material not 
covered by the standard specifications listed 
herein shall be investigated and tested to 
determine that it is safe and suitable for the 
proposed service and, in addition, shall be 
recommended for that service by the 
manufacturer and shall be acceptable to the 
Authority Having Jurisdiction. [NFPA 
54:5.6.1.3] 

1309.5.2 Metallic Pipe. 

1309.5.2.1 Cast-iron pipe shall not be used. 
[NFPA 54:5.6.2.1] 

1 309.5.2.2 Steel and wrought-iron pipe 
shall be at least of standard weight 
(Schedule 40) and shall comply with one of 
the following standards: [NFPA 54:5.6.2.2] 

(1) ASME B36.10, Welded and Seamless 
Wrought-Steel Pipe 

(2) ASTM A 53, Standard Specification for 
Pipe, Steel, Black and Hot-Dipped, Zinc- 
Coated Welded and Seamless 



204 



FUEL GAS PIPING 



1309.5 



(3) , ASTM A 106, Standard Specification for. 
. Seamless Carbon Steel Pipe for High- 
Temperature Service 

1 309.5.2.3 Copper and brass pipe shall not 
be used if the gas contains more than an 
average of 0.3 grains of hydrogen sulfide per 
100 scf of gas (0.7 mg/100 L). [NFPA 
54:5.6.2.3] 

Threaded copper, brass, or aluminum 
alloy pipe shall not be used with gases 
corrosive to such material. [NFPA 54:5.6.2.4] 

1309.5.2.4 Aluminum alloy pipe shall 
comply with ASTM B 241, Specification for 
Aluminum-Alloy Seamless Pipe and 
Seamless Extruded Tube (except that the use 
of alloy 5456 is prohibited) and shall be 
marked at each end of each length 
indicating compliance. Aluminum alloy 
pipe shall be coated to protect against 
external corrosion where it is in contact with 
masonry, plaster, or insulation, or is subject 
to repeated wettings by such liquids as 
water, detergents, or sewage. [NFPA 
54:5.6.2.5] 

Aluminum alloy pipe shall not be used 
in exterior locations or underground. [NFPA 
54:5.6.2.6] 

1309.5.3 Metallic Tubing. Seamless copper, 
aluminum alloy, or steel tubing shall not be used 
with gases corrosive to such material. [NFPA 
54:5.6.3] 

1309.5.3.1 Steel tubing shall comply with 
ASTM A 539, Standard Specification for 
Electric Resistance- Welded Coiled Steel 
Tubing for Gas and Fuel Oil Lines, or ASTM 
A 254, Standard Specification for Copper 
Brazed Steel Tubing. [NFPA 54;5.6.3.1] 

1 309.5.3.2 Copper and brass tubing shall not be 
used if the gas contains more than an average of 
0.3 g of hydrogen sulfide per 100 scf of gas (0.7 
mg/100 L). Copper tubing shall comply with 
standard Type K or L of ASTM B 88, 
Specification for Seamless Copper Water Tube, 
or ASTM B 280, Specification for Seamless 
Copper Tube for Air Conditioning and 
Refrigeration Field Service. [NFPA 54:5.6.3.2] . 

1309.5.3.3 Aluminum alloy tubing shall 
comply with ASTM B 210, Specification for 
Aluminum-Alloy Drawn Seamless Tubes, or 
ASTM B 241, Specification for Aluminum 
Alloy Seamless Pipe and Seamless Extended 
Tube. Aluminum alloy tubing shall be coated 



to protect against external corrosion where it 
is in contact with masonry, plaster, or 
insulation, or is subject to repeated wettings 
by such liquids as water, detergent, or 
sewage. Aluminum alloy tubing shall not be 
used in exterior locations or undergroimd. 
[NFPA 54:5.6.3.3] 

1309.5.3.4 Corrugated stainless steel tubing 
shall be tested and listed in compliance with 
the construction, installation, and performance 
requirements of IAS LC-1, Standard for Fuel 
Gas Piping Systems Using Corrugated 
Stainless Steel Tubing. [NFPA 54:5.6.3.4] 

1309.5.4 Plastic Pipe, Tubing, and Fittings. 

Plastic pipe, tubing, and fittings shall be used 
outside underground only and shall conform 
with ASTM D 2513, Standard Specification for 
Thermoplastic Gas Pressure Pipe, Tubing, and 
Fittings. Pipe to be used shall be marked "gas" 
and 'ASTM D 2513." [NFPA 54:5.6.4.1] 

Anodeless risers shall comply with the 
following: [NFPA 54:5.6.4.3] 

1309.5.4.1 Factory-assembled anodeless 
risers shall be recommended by the manu- 
facturer for the gas used and shall be leak- 
tested by the manufacturer in accordance 
with written procedures. 

1309.5.4.2 Service head adapters and field- 
assembled anodeless risers incorporating 
service head adapters shall be recommended 
by the manufacturer for the gas used by the 
manufacturer and shall be design-certified 
to meet the requirements of Category I of 
ASTM F1973, Standard Specification for 
Thermoplastic Gas Pressure Pipe, Tubing, 
and Fittings, and the Code of Federal 
Regulations, Title 49, Part 192.281(e). The 
manufacturer shall provide the user- 
qualified installation instructions as pre- 
scribed by the Code of Federal Regulations, 
Title 49, Part 192.283(b). 

1309.5.4.3 The use of plastic pipe, tubing, and 
fittings in imdUuted liquefied petroleum gas 
piping systems shall be in accordance with 
NFPA 58, Liquefied Petioleum Gas Code. 

1309.5.5 Worl<mansliip and Defects. Gas pipe, 
tubing, and fittings shall be clear and free from 
cutting burrs and defects in structure or threading 
and shall be thoroughly brushed and chip and 
scale blown. Defects in pipe, tubing, and fittings 
shall not be repaired. Defective pipe, tubing, and 
fittings shall be replaced. [NFPA 54:5.6.5] 



205 



1309.5 



2007 CALIFORNIA MECHANICAL CODE 



1309.5.6 Protective Coating. Where in contact 
with material or atmosphere exerting a corrosive 
action, metallic piping and fittings coated with a 
corrosion-resistant material shall be used. 
External or internal coatings or linings used on 
piping or components shall not be considered as 
adding strengtih.. [NFPA 54:5.6.6] 

1309.5.7 IVIetaliic Pipe Tiireads. 

(A) Specifications for Pipe Tiireads. Metallic 
pipe and fitting threads shall be taper pipe 
threads and shall comply with ASME Bl.20.1, 
Standard for Pipe Threads, General Purpose 
(Inch). [NFPA 54:5.6.7.1] 

(B) Damaged Tiireads. Pipe with threads that 
are stripped, chipped, corroded, or 
otherwise damaged shall not be used. 
Where a weld opens during the operation of 
cutting or threading, that portion of the pipe 
shall not be used. [NFPA 54:5.6.7.2] 

(C) Number of Tiireads. Field threading of 
metallic pipe shall be in accordance with 
Table 13-2. [NFPA 54:5.6.7.3] 

(D) Tiiread Compounds. Thread (joint) 
compoimds (pipe dope) shall be resistant to 
the action of liquefied petroleum gas or to 
any other chemical constituents of the gases 
to be conducted through the piping. 

TABLE 13-2 
Specifications for Tlireading IVIetallic Pipe 





Approximate Length 


Approximate 


Iron Pipe 


of Threaded 


No. of 


Size (in.) 


Portion (in.) 


Threads to Be Cut 


1/2 


3/4 


10 


3/4 


3/4 


10 


1 


7/8 


10 


1-1/4 


1 


11 


1-1/2 


1 


11 


2 


1 


11 


2-1/2 


1-1/2 


12 


3 


1-1/2 


12 


4 


1-5/8 


13 



Note: For SI tmits, 1 in. = 25.4 mm. [NFPA 54:5.6.7.3] 

1309.5.8 IVIetaliic Piping Joints and Fittings. 

The type of piping joint used shall be suitable for 



the pressure-temperature conditions and shall 
be selected giving consideration to joint 
tightness and mechanical strength under the 
service conditions. The joint shall be able to 
sustain the maximum end force due to the 
internal pressure and any additional forces due 
to temperature expansion or contraction, 
vibration, fatigue, or the weight of the pipe and 
its contents. [NFPA 54:5.6.8] 

1309.5.8.1 Pipe Joints. Pipe joints shall be 
threaded, flanged, brazed, or welded. Where 
nonferrous pipe is brazed, the brazing 
materials shall have a melting point in excess 
of 1,000°F (538°C). Brazing alloys shall not 
contain more than 0.05 percent phosphorus. 
[NFPA 54:5.6.8.1] 

1309.5.8.2 Tubing Joints. Tubing joints shall 
either be made with approved gas tubing 
fittings or be brazed with a material having a 
melting point in excess of 1,000°F (538°C). 
Brazing alloys shall not contain more than 
0.05 percent phosphorus. [NFPA 54:5.6.8.2] 

1309.5.8.3 Fiared Joints. Flared joints shall 
be used only in systems constructed from 
nonferrous pipe and tubing where experience 
or tests have demonstrated that the joint is 
suitable for the conditions and where 
provisions are made in the design to prevent 
separation of the joints. [NFPA 54:5.6.8.3] 

1309.5.8.4 IVIetaliic Fittings (Including 
Valves, Strainers, Filters). [NFPA 
54:5.6.8.4] 

(1) Threaded fittings in sizes larger than 
four (4) inches (100 mm) shall not be 
used tmless acceptable to the Authority 
Having Jurisdiction. 

(2) Fittings used with steel or wrought-iron 
pipe shall be steel, brass, bronze, 
malleable iron, or cast iron. 

(3) Fittings used with copper or brass pipe 
shall be copper, brass, or bronze. 

(4) Fittings used with aluminum alloy pipe 
shall be of aluminum alloy. 

(5) Cast-Iron Fittings. 

(a) Flanges shall be permitted. 

(b) Bushings shall not be used. 

(c) Fittings shall not be used in 
systems containing flammable 
gas-air mixtures. 

(d) Fittings in sizes four (4) inches (100 mm) 



206 



FUEL GAS PIPING 



1309.5 



^ 



and larger shall not be used 
indoors unless approved by the 
Authority Having Jurisdiction, 
(e) Fittings in sizes six (6) inches (150 iran) 
and larger shall not be used unless 
approved by the Authority Having 
Jurisdiction. 

(6) Aluminum Alloy Fittings. Threads 
shall not form the joint seal. 

(7) Zinc- Aluminum Alloy Fittings. Fittings 
shall not be used in systems containing 
flammable gas-air mixtures. 

(8) Special Fittings. Fittings such as 
couplings, proprietary-type joints, 
saddle tees, gland-type compression 
fittings, and flared, flareless, or 
compression-type tubing fittings shall 
be (1) used within the fitting 
manufacturer's pressure-temperature 
recommendations; (2) used within the 
service conditions anticipated with 
respect to vibration, fatigue, thermal 
expansion, or contraction; (3) installed 
or braced to prevent separation of the 
joint by gas pressure or external 
physical damage; and (4) acceptable to 
the Authority Having Jurisdiction. 

1309.5.9 Plastic Piping, Joints, and Fittings. 

Plastic pipe, tubing, and fittings shall be joined 
in accordance with the manufacturers' 
instructions. The following shall be observed 
when making such joints: [NFPA 54:5.6.9] 

(A) The joint shall be designed and installed 
so that the longitudinal pullout 
resistance of the joint will be at least 
equal to the tensile strength of the 
plastic piping material. 

(B) Heat-fusion joints shall be made in 
accordance with qualified procedures 
that have been established and proven 
by test to produce gastight joints at least 
as strong as the pipe or tubing being 
joined. Joints shall be made with the 
joining method recommended by the 
pipe manufacturer. Heat fusion fittings 
shall be marked "ASTM D 2513." 

(C) Where compression-type mechanical 
joints are used, the gasket material in 
the fittings shall be compatible with the 
plastic piping and with the gas 
distributed by the system. An internal 

J tubular rigid stiffener shall be used in 

conjunction with the fitting. The 



stiffener shall be flush with the end of 
the pipe or tubing and shall extend at 
least to the outside end of the pipe or 
tubing and shall extend at least to the 
outside end of the compression fitting 
when installed. The stiffener shall be 
free of rough or sharp edges and shall 
not be a force-fit in the plastic. Split 
tubular stiffeners shall not be used. 

(D) Plastic piping joints and fittings for use 
in liquefied petroleum gas piping 
systems shall be in accordance with 
Liquefied Petroleum Gas Code, NFPA 58. 

1309.5.10 Flanges. All flanges shall comply 
with ASME B16.1, Standard for Cast Iron Pipe 
Flanges and Flanged Fittings; ASME B16.20, 
Standard for Ring-Joint Gaskets and Grooves for 
Steel Pipe Flanges; or MSS SP-6, Standard 
Finishes for Contact Faces of Pipe Flanges and 
Connecting-End Flanges of Valves and Fittings. 
The pressure-temperature ratings shall equal or 
exceed that required by the application. [NFPA 
54:5.6.10] 

(A) Flange Facings. Standard facings shall be 
permitted for use under this code. Where 
150 psi (1,090 kPa) steel flanges are bolted to 
Class 125 cast-iron flanges, the raised face 
on the steel flange shall be removed. [NFPA 
54:5.6.10.1] 

(B) Lapped Flanges. Lapped flanges shall be 
used only aboveground or in exposed 
locations accessible for inspection. [NFPA 
54:5.6.10.2] 

1309.5.11 Flange Gaskets. The material for 
gaskets shall be capable of withstanding the 
design temperature and pressure of the piping 
system and the chemical constituents of the gas 
being conducted without change to its chemical 
and physical properties. The effects of fire 
exposure to the joint shall be considered in 
choosing the material. [NFPA 54:5.6:11] 

(1) Acceptable materials include the following: 
[NFPA 54:5.6.11.1] 

(a) Metal or metal-jacketed asbestos (plain 
or corrugated) 

(b) Asbestos 

(c) Aluminum O-rings and spiral-wound 
metal gaskets 

(2) When a flanged joint is opened, the gasket 
shall be replaced. [NFPA 54:5.6.11.2] 

(3) Full-face gaskets shall be used with all 
bronze and cast-iron flanges. [NFPA 
54:5.6.11.3] 



207 



1309.6-1309.7 



2007 CALIFORNIA MECHANICAL CODE 



1309.6 Gas Meters. 

1309.6.1 Capacity. Gas meters shall be selected 
for the maximum expected pressure and 
permissible pressure drop. 

1309.6.2 Location. [NFPA 54:5.7.1] 

(A) Gas meters shall be located in ventilated 
spaces readily accessible for examination, 
reading, replacement, or necessary 
maintenance. [NFPA 54:5.7.2.1] 

(B) Gas meters shall not be placed where they 
will be subjected to damage, such as 
adjacent to a driveway, imder a fire escape, 
in public passages, halls, or coal bins, or 
where they will be subject to excessive 
corrosion or vibration. [NFPA 54:5.7.2.2] 

(C) Gas meters shaU be located at least three (3) 
feet (0.9 m) from sources of ignition. [NFPA 
54:5.7.2.3] 

(D) Gas meters shall not be located where they 
will be subjected to extreme temperattires or 
sudden extreme changes in temperature. 
Meters shall not be located in areas where 
they are subjected to temperatures beyond 
those recommended by the manufacturer. 
[NFPA 54:5.7.2.3] 

1309.6.3 Supports. Gas meters shall be 
supported or connected to rigid piping so as not 
to exert a strain on the meters. Where flexible 
coi\nectors are used to connect a gas meter to 
downstream piping at mobile homes in mobile 
home parks, the meter shall be supported by a 
post or bracket placed in a firm footing or by 
other means providing equivalent support. 
[NFPA 54:5.7.3] 

1309.6.4 IVIeter Protection. Meters shall be 
protected against overpressure, back pressure, and 
vacuum, where such conditions are anticipated. 

1309.6.5 Identification. Gas piping at multiple 
meter installations shall be marked by a metal tag 
or other permanent means attached by the 
installing agency, designating the building or the 
part of the building being supplied. [NFPA 54:5.7.5] 

1309.7 Gas Pressure Regulators. 

1309.7.1 Where Required. A line gas pressure 
regulator or gas equipment pressure regulator, 
as applicable, shall be installed where the gas 
supply pressure is higher than that at which the 
branch supply line or gas utilization equipment 
is designed to operate or varies beyond design 
pressure limits. [NFPA 54:5.8.1] 

1309.7.2 Listing. Line gas pressure regulators 



shall be listed in accordance with ANSI Z21.80. 
[NFPA 54:5.8.2] 

1309.7.3 Location. The gas pressure regulator 
shall be accessible for servicing. [NFPA 54:5.8.3] 

1309.7.4 Regulator Protection. Pressure 
regulators shall be protected against physical 
damage. [NFPA 54:5.8.4] 

1309.7.5 Venting. 

(A) Line Gas Pressure Regulators. [NFPA 54:5.8.5.1] 

(1) An independent vent to the outside of the 
building, sized in accordance with the 
regulator manufacturer's instructions, shall 
be provided where the location of a 
regiilator is such that a ruptured diaphragm 
will cause a hazard. Where there is more 
than one regulator at a location, each 
regulator shall have a separate vent to the 
outside, or if approved by the Authority 
Having Jurisdiction, the vent lines shall be 
permitted to be manifolded in accordance 
with accepted engineering practices to 
minimize back pressure in the event of 
diaphragm failure. (See NFPA 54:5.9.7 for 
information on properly locating the 
vent.) Materials for vent piping shall be in 
accordance with Section 1309.5. 

Exception: A regulator and vent- 
limiting means combination listed as 
complying with ANSI Z21.80, Standard 
for Line Pressure Regulators, shall be 
permitted to be used without a vent to 
the outdoors. 

The following references were extracted from 
NFPA 54: 

5.9.7 Vents. The discharge stacks, vents or outlet 
farts of all -pressure-relieving and pressure- 
limiting devices shall he located so that gas is 
safely discharged into the outside atmosphere. 
Discharge stacks or vents shall be designed to 
prevent the entry of water, insects, or any other 
foreign material that could cause blockage. The 
discharge stack or vent line shall be at least the 
same size as the outlet of the pressure-relieving 
device. 

(2) The vent shall be designed to prevent the 
entry of water, insects, or other foreign 
materials that could cause blockage. 

(3) At locations where regulators might be 
submerged during floods, a special 
antiflood-type breather vent fitting shall be 
installed, or the vent line shall be 
extended above the height of the expected 
flood waters. 



208 



FUEL GAS PIPING 



1309.7-1310.0 



(4) A regulator shall not be vented to the gas 
equipment flue or exhaust system. 

(B) Gas Appliance Pressure Regulators. For 

venting of gas appliance pressure regulators (see 
Section 1310.0). 

1309.7.6 Bypass Piping. Valved and regulated 
bypasses shall be permitted to be placed around 
gas line pressure regulators where continuity of 
service is imperative. [NFPA 54:5.8.6] 

1309.7.7 Identification. Line pressure regulators 
at multiple regulator installations shall be 
marked by a metal tag or other permanent 
means designating the building or the part of the 
building being supplied. [NFPA 54:5.8.7] 

1309.8 Back-Pressure Protection. 

1309.8.1 Where to Install. Protective devices shall 
be installed as close to the utilization equipment as 
practical where the design of utilization equipment 
connected is such that air, oxygen, or standby 
gases could be forced into the gas supply system. 
[NFPA 54:5.10.1.1] Gas and air combustion mixers 
incorporating double diaphragm "zero" or 
"atmosphere" governors or regulators shall require 
no furflier protection unless connected directly to 
compressed air or oxygen at pressures of 5 psi (34 
kPa) or more. [NFPA 54:5.10.1.2] 

1309.8.2 Protective Devices. Protective devices 
shall include, but not be limited to, the 
foUowing: [NFPA 54:5.10.2] 

(1) Check valves. 

(2) Three-way valves (of the type that 
completely closes one side before starting to 
open the other side). 

(3) Reverse flow indicators controlling positive 
shutoff valves. 

(4) Normally closed air-actuated positive 
shutoff pressure regulators. 

1309.9 Low-Pressure Protection. A protective device 
shall be installed between the meter and the gas 
utilization equipment if the operation of the equipment 
is such (i.e., a gas compressor) that it covild produce a 
vacuum or a dangerous reduction in gas pressure at the 
meter. Such devices include, but are not limited to, 
mechanical, diaphragm-operated, or electrically 
operated low-pressure shutoff valves. [NFPA 54:5.11] 

1309.10 Shutoff Valves. Shutoff valves shall be 
approved and shall be selected giving consideration 
to pressure drop, service involved, emergency use, 
and reliability of operation. Shutoff valves of size 1 
inch National Pipe Thread and smaller shall be 
listed. [NFPA 54:5.12] 

1309.11 Expansion and Flexibility. 

1309.11.1 Design. Piping systems shall be 



designed to have sufficient flexibility to prevent 
thermal expansion or contraction from causing 
excessive stresses in the piping material, 
excessive bending or loads at joints, or imdesirable 
forces or moments at points of connections to 
equipment and at anchorage or guide points. 
Formal calculations or model tests shall be 
required only where reasonable doubt exists as 
to the adequate flexibility of the system. [NFPA 
54:5.13.1] Flexibility shall be provided by the use 
of bends, loops, offsets, or couplings of the slip 
tj^e. Provision shall be made to absorb thermal 
changes by the use of expansion joints of the 
bellows type or by the use of ball or swivel joints. 
Expansion joints of the sUp type shall not be used 
inside btiildings or for thermal expansion. Where 
expansion joints are used, anchors or ties of 
sufficient strength and rigidity shall be installed 
to provide for end forces due to fluid pressure 
and otiier causes. [NFPA 54:5.13.1.1] 

Pipe alignment guides shall be used with 
expansion joints, according to the recomnaended 
practice of the joint manufacturer. [NFPA 
54:5.13.1.2] 

1309.11.2 Special Local Conditions. Where 

local conditions include earthquake, tornado, 
unstable ground, or flood hazards, special 
consideration shall be given to increased 
strength and flexibility of piping supports and 
connections. [NFPA 54:5.13.2] 

1310.0 Venting of Gas Appliance Pressure 
Regulators. Venting of gas appliance pressure 
regulators shall comply with the following 
requirements: [NFPA 54:9.1.19] 

(1) Gas appliance pressure regulators requiring 
access to the atmosphere for successful 
operation shall be equipped with vent 
piping leading outdoors or, if the regulator 
vent is an integral part of the equipment, 
into the combustion chamber adjacent to a 
continuous pilot, unless constructed or 
equipped with a vent-limiting means to 
limit the escape of gas from the vent 
opening in the event of diaphragm failure. 

(2) Vent-limiting means shall be employed on 
listed gas appliance pressure regulators 
only. 

(3) In the case of vents leading outdoors, means 
shall be employed to prevent water from 
entering this piping and also to prevent 
blockage of vents by insects and foreign 
matter. 



209 



1310.0-1311.1 



2007 CALIFORNIA MECHANICAL CODE 



(4) Under no circumstances shall a regulator be 
vented to the gas utilization equipment flue 
or exhaust system. 

(5) In the case of vents entering the combustion 
chamber, the vent shall be located so the 
escaping gas will be readily ignited by the 
pilot and the heat liberated thereby will 
not adversely affect the normal operation of 
the safety shutoff system. The terminus of 
the vent shaU be securely held in a fixed 
position relative to the pilot. For man- 
ufactured gas, the need for a flame arrester 
in the vent piping shaU be determined. 

(6) Vent line(s) from a gas appliance pressure 
regulator and bleed line(s) from a 
diaphragm-type valve shall not be 
connected to a common manifold termina- 
ting in a combustion chamber. Vent 
lines shall not terminate in positive- 
pressure-type combustion chambers. 

1311.0 Gas Piping Installation. 

1311.1 Piping Underground. 

1311.1.1 Clearances. Underground gas piping 
shall be installed with sufficient clearance from 
any other underground structure to avoid 
contact therewith, to allow maintenance, and to 
protect against damage from proximity to other 
structures. In addition, underground plastic 
piping shall be installed with sufficient clearance 
or shall be insulated front any soxirce of heat so 
as to prevent the heat from impairing the 
serviceability of the pipe. [NFPA 54:7.1.1] 

1311.1.2 Protection Against Damage. 

(A) Cover Requirements. Undergroimd piping 
systems shall be installed with a minimum 
of eighteen (18) inches (460 mm) of cover. 
Where external damage to the pipe is not 
likely to result, the minimtun cover shall be 
twelve (12) inches (300 mm). Where a 
minimiim of twelve (12) inches (300 mm) of 
cover cannot be provided, the pipe shall be 
installed in conduit or bridged (shielded). 
[NFPA 54:7.1.2.1] 

(B) Trenches. The trench shall be graded so 
that the pipe has a firm, substantially 
continuous bearing on the bottom of the 
trench. [NFPA 54:7.1.2.2] 

(C) Backfilling. Where flooding of the french is 
done to consolidate the backfill, care shall be 
exercised to see that the pipe is not floated 
from its firm bearing on the french bottom. 
[NFPA 54:7.1.2.3] 

1311.1.3 Protection Against Corrosion. Gas 

piping in contact with earth or other material 



that could corrode the piping shall be protected 
against corrosion in an approved manner. When 
dissimilar metals are joined underground, an 
insulating coupling or fitting shall be used. 
Piping shall not be laid in contact with cinders. 
Uncoated threaded or socket-welded joints shall 
not be used in piping in contact with soil or 
where internal or external crevice corrosion is 
known to occur. [NFPA 54:7.1.3] 

1311.1.4 Protection Against Freezing. Where 
the formation of hydrates or ice is known to 
occur, piping shall be protected against freezing. 
[NFPA 54:7.1.4] 

1311.1.5 Piping Through Foundation Wall. 

Undergroimd piping, where installed through the 
outer foundation or basement wall of a building, shall 
be encased in a protective pipe. The space between the 
gas piping and the building shall be sealed to prevent 
entiy of gas or water. [NFPA 54:7.1.5] 

1311.1.6 Piping Underground Beneath Buildings. 

Where the installation of gas piping imderground 
beneath buildings is xmavoidable, the piping shaU 
be encased in an approved conduit designed to 
withstand the superimposed loads. [NFPA 54:7.1.6] 
The conduit shall extend into a normally usable and 
accessible portion of the building and, at the point 
where the condtut terminates in the building, the 
space between the conduit and the gas piping shall 
be sealed to prevent the possible enfrance of any gas 
leakage. Where the end sealing is of a type that will 
retain the fuU pressure of the pipe, the conduit shall 
be designed for the same pressure as the pipe. The 
conduit shall extend at least four (4) inches (100 
mm) outside the building, be vented above grade to 
the outside, and be installed so as to prevent the 
enfrance of water and insects. [NFPA 54:7.1.6.1] 

1311.1.7 Plastic Pipe. 

(A) Connection of Plastic Piping. Plastic pipe 
shall be installed outside, underground 
only.[NFPA 54:7.1.7.1] 

Exceptions: 

(1) Plastic pipe shall be permitted to 
terminate aboveground where an 
anodeless riser is used. 

(2) Plastic pipe shall be permitted to 
terminate with a wall head adapter 
aboveground in buildings, including 
basements, where the plastic pipe is 
inserted in a piping material permitted 
for use in buUdings. 

(B) Connections made outside and undergroimd 
between metallic and plastic piping shall be 
made only with ASTM D 2513, Standard 
Specification for Thermoplastic Gas Pressure 



210 



FUEL GAS PIPING 



1311.2 



Pipe, Tubing, and Fittings, Category I transition 
fittings. [NFPA 54:7.1.7.2] 

(C) An electrically continuous corrosion- 
resistant tracer wire (minimum AWG 14) or tape 
shall be buried with the plastic pipe to facilitate 
locating. One end shall be brought aboveground 
at a building wall or riser. [NFPA 54:7.1.7.3] 

1311.2 Installation of Piping. 

1311.2.1 Piping installed aboveground shall be 
securely supported and located where it will be 
protected from physical damage (also see 
1311.1.4). Where passing through an outside 
wall, the piping shall also be protected against 
corrosion by coating or wrapping with an inert 
material approved for such applications. Where 
piping is encased in a protective pipe sleeve, the 
armular space between the gas piping and the 
sleeve shall be sealed at the wall to prevent the 
entry of water, insects, or rodents. [NFPA 
54:7.2.1] 

1311 .2.2 Building Structure. 

(1) The installation of gas piping shall not cause 
structural stresses within building 
components to exceed allowable design limits. 
[NFPA 54:7.2.2.1] 

(2) Approval shall be obtained before any 
beams or joists are cut or notched. 

[NFPA 54:7.2.2.2] 

1311.2.3 Other Than Dry Gas. Drips, sloping, 
protection from freezing, and branch pipe 
connections, as provided for in Sections 1311.1.4, 
1311.6.1, and 1311.8, shall be provided when 
other than dry gas is distributed and climatic 
conditions make such provisions necessary. 
[NFPA 54:7.2.3] 

1311.2.4 Gas Piping to be Sloped. Piping for 
other than dry gas conditions shall be sloped not 
less than 1/4 inch in fifteen (15) feet (7 mm in 4.6 
m) to prevent traps. [NFPA 54:7.2.4] 

1311.2.4.1 Ceiling Locations. Gas piping 
shall be permitted to be installed in 
accessible spaces between a fixed ceiling and 
a dropped ceiling, whether or not such 
spaces are used as a plenum. Valves shall 
not be located in such spaces. 

Exception: Equipment shutoff valves 
required by this code shall be permitted 
to be installed in accessible spaces 
containing vented gas utilization 
equipment. 

1311.2.5 Prohibited Locations. Gas piping 
inside any building shall riot be installed in or 
through a circulating air duct, clothes chute, 
chimney or gas vent, ventilating duct, dimibwaiter. 



or elevator shaft. This provision shall not apply to 
ducts used to provide combustion and ventilation 
air in accordance with Section 701.0 or to above- 
ceiling spaces as covered in 1311.2.4.1. 

1311.2.6 Hangers, Supports, and Anchors. 

(A) Piping shall be supported with pipe hooks, 
metal pipe straps, bands, brackets, or hangers 
suitable for the size of piping, of adequate 
strength and quality, and located at intervals so 
as to prevent or damp out excessive vibration. 
Piping shall be anchored to prevent undue 
strains on connected equipment and shall not be 
supported by other piping. Pipe hangers and 
supports shall conform to the requirements of 
MSS SP-58, Pipe Hangers and Supports - 
Materials, Design and Manufacture. [NFPA 
54:7.2.6.1] 

(B) Spacings of supports in gas piping 
installations shall not be greater than shown in 
Table 13-3. Spacing of supports for CSST shall be 
in accordance with the CSST manufacturer's 
instiruction. [NFPA 54:7.2.6.2] 

(C) Supports, hangers, and anchors shall be 
installed so as not to interfere with the' free 
expansion and contraction of the piping between 
anchors. All parts of the supporting equipment 
shall be designed and installed so they wiU not be 
disengaged by movement of the supported piping. 
[NFPA 54:7.2.6.3] 

TABLE 13-3 
Support of Piping 



steel Pipe, 


Spacing of 


Nominal Size of 


Spacing of 


Nominal Size 


Supports 


Tubing 


Supports 


of Pipe 


(ft.) 


Smooth-wall 


(ft.) 


(in.) 




(inch O.D.) 




1/2 


6 


1/2 


4 


3/4 or 1 


8 


5/8 or 3/4 


6 


1-1/4 or larger 


10 


7/8 or 1 


8 


(horizontal) 




(horizontal) 




1-1/4 or larger 


Every floor 


1 or larger 


Every floor 


(vertical) 


level 


(vertical) 


level 



Note: For SI tiTuts: 1 ft. = 0.305 m. [NFPA 54:7.2.6.2] 

1311.2.7 Removal of Pipe. Where piping 
containing gas is to be removed, the line shall be first 
disconnected from all sources of gas and then 
thoroughly purged with air, water, or inert gas before 
any cutting or welding is done. (See Section 1314.7.1.) 
[NFPA 54:7.2.7] 



211 



1311.3-1311.4 



2007 CALIFORNIA MECHANICAL CODE 



1311.3 Concealed Piping Building. 

1311.3.1 General. Gas piping in concealed 
locations shall be installed in accordance with 
this section. [NFPA 54:7.3.1] 

1311.3.2 Connections. Where gas piping is to 
be concealed, unions, tubing fittings, right and 
left couplings, bushings, swing joints, and 
compression couplings made by combinations of 
fittings shall not be used. Connections shall be of 
the following type: [NFPA 54:7.3.2] 

(1) Pipe fittings, such as elbows, tees, and 
couplings. 

(2) Joining tubing by brazing (See Section 
1309.5.8.2.). 

(3) Fittings listed for use in concealed spaces 
that have been demonstrated to sustain, 
without leakage, any forces due to 
temperature expansion or contraction, 
vibration, or fatigue based on their 
geographic location, application, or operation. 

(4) Where necessary to insert fittings in gas pipe 
that has been installed in a concealed 
location, the pipe shall be recormected by 
welding, flanges, or the use of a ground 
joint union with the nut center-punched to 
prevent loosening by vibration. 

1311.3.3 Piping in Partitions. Concealed gas 
piping shall not be located in solid partitions. 
[NFPA 54:7.3.3] 

1311.3.4 Tubing in Partitions. This provision 
shall not apply to tubing that pierces walls, 
floors, or partitions. Tubing installed vertically 
and horizontally inside hollow walls or 
partitions without protection along its entire 
concealed length shall meet the following 
requirements: [NFPA 54:7.3.4] 

(1) A steel striker barrier not less than 0.0508 
inch (1.3 mm) thick, or equivalent, is installed 
between the tubing and the finished wall 
and extends at least four (4) inches (100 mm) 
beyond concealed penetrations of plates, fire- 
stops, wall studs, and so on. 

(2) The tubing is installed in single runs and is 
not rigidly secured. 

1311.3.5 Piping in Floors. In industrial 
occupancies, gas piping in solid floors such as 
concrete shall be laid in channels in the floor and 
covered to permit access to the piping with a 
minimum of damage to the building. Where 
piping in floor channels could be exposed to 
excessive moisture or corrosive substances, the 
pipiing shall be protected in an approved marmer. 

Exception: In other than industrial occupan- 



cies and where approved by the Authority 
Having Jurisdiction, gas piping embedded in 
concrete floor slabs constructed with 
Portland cement shall be surrounded with a 
minunum of 1-1/2 inch (38 mm) of concrete 
and shall not be in physical contact with 
other metallic structures, such as reinforcing 
rods or electrically neutral conductors. All 
piping, fittings, and risers shall be protected 
against corrosion in accordance wilh Section 
1309.5.6. Piping shall not be embedded in 
concrete slabs containing quickset additives 
or cinder aggregate. [NFPA 54:7.3.5.2] 

1311.4 Piping in Vertical Chases. (See Section 
1302.0) Where gas piping exceeding five (5) psi (34 
kPa) is located within vertical chases in accordance 
with NFPA 54 Section 5.5.1(2), the requirements of 
Sections 1311.4.1 through 1311.4.3 shall apply. 
[NFPA 54:7.4] 

The following references were extracted from NFPA 54: 

5.5.1 Maximum Design Operating Pressure. The 
maximum design operating pressure for piping 
systems located inside buildings shall not exceed 5 psi 
(34 kPa) unless one or more of the following 
conditions are met: 

(1) The piping system is welded. 

(2) The piping is located in a ventilated chase or 
otherwise enclosed for protection against accidental 
gas accumulation. 

(3) The piping is located inside buildings or separate 
areas of buildings used exclusively for one of the 
following: 

(a) Industrial processing or heating 

(b) Research 

(c) Warehousing 

(d) Boiler or mechanical equipment rooms 

(4) The piping is a temporary installation for building 
under construction. 

1311.4.1 Pressure Reduction. (See Section 
1302) Where pressure reduction is required in 
branch coimections for compliance with NFPA 
54 Section 5.5.1, such reduction shall take place 
either inside the chase or immediately adjacent 
to the outside wall of the chase. Regulator 
venting and downstream overpressure 
protection shall comply with Section 1309.7.5. 
The regulator shall be accessible for service and 
repair and vented in accordance with one of the 
foUowing:[NFPA 54:7.4.1] 

(1) Where the fuel gas is lighter than air, 
regulators equipped with a vent-limiting 
means shall be permitted to be vented into 
the chase. Regulators not equipped with a 



212 



FUEL GAS PIPING 



1311.4-1311.7 



vent-limiting means shall be permitted to be 
vented either directly to the outdoors or to a 
point within the top one (1) foot (0.3m) of 
the chase. 

(2) Where the fuel gas is heavier than air, the 
regulator vent shall be vented only directly 
to the outdoors. 

1311.4.2 Construction. Chase construction 
shall comply with local building codes with 
respect to fire resistance and protection of 
horizontal and vertical openings. [NFPA 
54:7.4.2] 

1 31 1 .4.3 Ventilation. A chase shall be ventilated 
to the outdoors and only at the top. The 
opening(s) shall have a minimum free area (in 
square inches) equal to the product of one-half 
of the maximum pressure in the piping (in psi) 
times the largest nominal diameter of that piping 
(in inches), or the cross-sectional area of the 
chase, whichever is smaller. Where more than 
one fuel gas piping system is present, the free 
area for each system shaU be calculated and the 
largest area used. [NFPA 54:7.4.3] 

1311.5 Gas Pipe Turns. Changes in direction of gas 
pipe shall be made by the use of fittings or factory 
bends. [NPPA 54:7.5] 

1311.5.1 Metaliic Pipe. Metallic pipe bends 
shall comply with the following: [NFPA 54:7.5.1] 

(1) Bends shall be made only with bending 
equipment and procedures intended for that 
purpose. 

(2) All bends shall be smooth and free from 
buckling, cracks, or other evidence of mechanical 
damage. 

(3) The longitudinal weld of the pipe shall be 
near the neutral axis of the bend. 

(4) Pipe shall not be bent through an arc of 
more than 90 degrees. 

(5) The inside radius of a bend shall be not less 
than six times the outside diameter of the 
pipe. 

1311.5.2 Plastic Pipe. Plastic pipe bends shaU 
comply with the following: [NFPA 54:7.5.2] 

(1) The pipe shall not be damaged, and the 
internal diameter of the pipe shall not be 
effectively reduced. 

(2) Joints shall not be located in pipe bends. 

(3) The radius of the inner curve of such bends 
shall not be less than 25 times the inside 
diameter of the pipe. 

: ■ i(4) Where the piping manufacturer specifies the 
use of special bending equipment or 



procedures, such equipment or procedures 
shall be used. 

131 1 .5.3 Elbows. Factory-made welding elbows 
or transverse segments cut therefrom shall have 
an arc length measured along the crotch of at 
least one (1) inch (25 mm) for pipe sizes two (2) 
inches and larger. [NFPA 54:7.5.3] 

1311.6 Drips and Sediment Traps. 

1311.6.1 Provide Drips Where Necessary. For 

other than dry gas conditions, a drip shall be 
provided at any point in the line of pipe where 
condensate could collect. Where required by the 
Authority Having Jurisdiction or the serving gas 
supplier, a drip shall also be provided at the 
outlet of the meter. This drip shall be so installed 
as to constitute a trap wherein an accumulation 
of condensate will shut off the flow of gas before 
it will nm back into the meter. [NFPA 54:7.6.1] 

1311.6.2 Location of Drips. All drips shall be 
installed only in such locations that they will be 
readily accessible to permit cleaning or 
emptying. A drip shall not be located where the 
condensate is likely to freeze. [NFPA 54:7.6.2] 

1 31 1 .6.3 Sediment Traps. (See Section 1312.7.) 

1311.7 Outlets. 

1311.7.1 Location and Installation. 

(1) The outlet fittings or piping shall be securely 
fastened in place. [NFPA 54:7.7.1.1] 

(2) Outlets shall not be located behind doors. 
[NFPA 54:7.7.1.2] 

(3) Outlets shall be located far enough from 
floors, walls, patios, slabs, and ceilings to 
permit the use of wrenches without 
straining, bending, or damaging the piping. 
[NFPA 54:7.7.1.3] 

(4) The unthreaded portion of gas piping 
outlets shall extend not less than (1) inch (25 
mm) through finished ceilings or indoor or 
outdoor walls. [NFPA 54:7.7.1.4] 

(5) The unthreaded portion of gas piping 
outlets shall extend not less than two (2) 
inches (50 mm) above the surface off floors or 
outdoor patios or slabs. [NFPA 54:7.7.1.5] 

(6) The provisions of Section 1311.7.1(4) and (5) 
shall not apply to listed quick disconnect 
devices of the flush-mounted type or listed 
gas convenience outlets. Such devices shall 
be installed in accordance with the 
manufacturers' installation instructions. 
[NFPA 54:7.7.1.6] 

1311.7.2 Cap All Outlets. 

(A) Each outlet, including a valve, shall be 



213 



1311.7-1311.12 



2007 CALIFORNIA MECHANICAL CODE 



closed gastight with a threaded plug or cap 
immediately after installation and shall be 
left closed until the gas utilization eqtiipment 
is connected thereto. When equipment is 
discoimected from an outlet and the outlet is 
not to be used again immediately, it shall be 
closed gastight. [NFPA 54:7.7.2.1] 

Exceptions: 

(1) Laboratory eqtiipment installed in accordance 
with 1312.2(A) shall be permitted. 

(2) The use of a listed quick-disconnect device 
with integral shutoff or listed gas convenience 
outlet shall be permitted. 

(B) Equipment shutoff valves installed in 
fireplaces shall be removed and the piping 
capped gastight where the fireplace is used 
for solid-ftiel burning. [NFPA 54:7.7.2.2] 

1311.8 Branch Pipe Connection. When a branch 
outlet is placed on a main supply line before it is 
known what size pipe will be coimected to it, the 
outlet shall be of the same size as the line that 
suppUes it. [NFPA 54:7.8] 

1311.9 lUianuai Gas Sliutoff Vaives. See Section 
1312.4. 

1311.9.1 Vaives at Reguiators. An accessible 
gas shutoff valve shall be provided upstream of 
each gas pressure regulator. Where two gas 
pressure regulators are installed in series in a 
single gas line, a manual valve shall not be 
required at the second regulator. [NFPA 54:7.9.1] 

1311.9.2 Valves Controiiing IViuitipie Systems. 

(A) Accessibiiity of Gas Vaives. Main gas 
shutoff valves controlling several gas piping 
systems shall be readily accessible for operation 
and installed so as to be protected from physical 
damage. They shall be marked with a metal tag 
or other permanent means attached by the 
installing agency so that the gas piping systems 
supplied through them can be readily identified. 
[NFPA 54:7.9.2.1] 

(B) Sliutoff Vaives for iViultipie l4ouse Lines. 

In multiple tenant buildings supplied through a 
master meter, or through one service regulator 
where a meter is not provided, or where meters 
or service regulators are not readily accessible 
from the equipment location, an individual 
shutoff valve for each apartment or tenant line 
shall be provided at a convenient point of 
general accessibihty. 

In a common system serving a number of 
individual buildings, shutoff valves shall be 
installed at each building. [NFPA 54:7.9.2.2] 



1311.9.3 Emergency Siiutoff Vaives. An 

exterior shutoff valve to permit turning off the 
gas supply to each building in an emergency 
shall be provided. The emergency shutoff valves 
shall be plainly marked as such and their 
locations posted as required by the Authority 
Having Jurisdiction. [NFPA 54:7.9.2.3] 

1311.10 Profiibited Devices. No device shall be 
placed inside the gas piping or fittings that will 
reduce the cross-sectional area or otherwise obstruct 
the free flow of gas, except where proper allowance 
in the piping system design has been made for such 
a device and where approved by the Authority 
Having Jurisdiction. [NFPA 54:7.10] 

1311.11 Systems Containing Gas-Air lUllxtures 
Outside tlie Fiammabie Range. Where gas-air 
mixing machines are employed to produce 
mixtures above or below the flammable range, they 
shall be provided with stops to prevent adjustment 
of the mixture to within or approaching the 
flarrunable range. [NFPA 54:7.11] 

1311.12 Systems Containing Fiammabie Gas-Air 
IVIixtures. 

1311.12.1 Required Components. A central 
premix system with a flammable mixture in the 
blower or compressor shall consist of the 
following components: [NFPA 54:7.12.1] 

(1) Gas-mixing machine in the form of an 
automatic gas-air proportioning device 
combined with a downstream blower or 
compressor. 

(2) Flammable mixture piping, minimum 
Schedule 40 NPS. 

(3) Automatic firecheck(s). 

(4) Safety blowout(s) or backfire preventers for 
systems utilizing flammable mixture lines 
above 2-1/2 inch nominal pipe size or the 
equivalent. 

1311.12.2 Optional Components. The following 
components shall also be permitted to be 
utilized in any type of central premix system: 
[NFPA 54:7.12.2] 

(1) Flowmeter(s) 

(2) Flame arrester(s) 

1311.12.3 Additional Requirements. Gas- 
mixing machines shall have nonsparking 
blowers and shall be so constructed that a 
flashback will not rupture machine casings. 
[NFPA 54:7.12.3] 

1311.12.4 Special Requirements for Mixing 
Blowers. A mixing blower system shall be 
limited to applications with minimimi practical 
lengths of mixture piping, limited to a maximum 
mixture pressure of ten (10) inches water coltimn 



214 



FUEL GAS PIPING 



1311.11 -1311.12 



(25 Pa) and limited to gases containing no more 
than 10 percent hydrogen. 

The blower shall be equipped with a gas- 
control valve at its air entrance so arranged that 
gas is admitted to the airstream, entering the 
blower in proper proportions for correct 
combustion by the type of burners employed, 
the said gas-control valve being of either the 
zero governor or mechanical ratio valve type 
that controls the gas and air adjustment 
simultaneously. No valves or other obstructions 
shall be installed between the blower discharge 
and the burner or burners. [NFPA 54:7.12.4] 

1311.12.5 Installation of Gas-Mixing IVIachines. 

(A) The machine shall be located in a large, 
well-ventilated area or in a small detached 
building or cutoff room provided with room 
construction and explosion vents in accor- 
dance with sound engineering principles. 
Such rooms or below-grade installations 
shall have adequate positive ventilation. 
[NFPA 54:7.12.5.1] 

(B) Where gas-mixing machines are installed in 
well-ventilated areas, the type of electrical 
equipment shall be in accordance with 
NFPA 70, National Electrical Code, for 
general service conditions unless other 
hazards in the area prevail. Where gas- 
mixing machines are installed in small 
detached buildings or cutoff rooms, the 
electrical equipment and wiring shall be 
installed in accordance with NFPA 70, 
National Electrical Code, for hazardous 
locations (Articles 500 and 501, Class I, 
Division 2). [NFPA 54:7.12.5.2] 

(C) Air intakes for gas-mixing machines using 
compressors or blowers shall be taken from 
outdoors whenever practical. 

[NFPA 54:7.12.5.3] 

(D) Controls for gas-mixing machines shall 
include interlocks and a safety shutoff valve 
of the manual reset tjrpe in the gas supply 
connection to each machine arranged to 
automatically shut off the gas supply in the 
event of high or low gas pressure. Except for 
open-burner installations only, the controls 
shall be interlocked so that the blower or 
compressor will stop operating following a 
gas supply failure. Where a system employs 
pressurized air, means shall be provided to 
shut off the, gas supply in the event of air 
failure. [NFPA 54:7.12.5.4] 

(E) Centrifugal gas-mixing machines in parallel 
shall be reviewed by the user and equip- 
ment manufacturer before installation, and 



means or plans for minimizing these effects 
of downstream pulsation and equipment 
overload shall be prepared and utilized as 
needed. [NFPA 54:7.12.5.5] 

1311.12.6 Use of Automatic Firechecks, 
Safety Blowouts, or Backfire Preventers. 

Automatic firechecks and safety blowouts or 
backfire preventers shall be provided in piping 
systems distributing flammable air-gas mixtures 
from gas-mixing machines to protect the piping 
and the machines in the event of flashback, in 
accordance with the following: [NFPA 
54:7.12.5.6] 

(A) Approved automatic firechecks shall be 
installed upstream as close as practicable to 
the burner inlets following the firecheck 
manufacturer's instructions. 

(B) A separate manually operated gas valve 
shall be provided at each automatic 
firecheck for shutting off the flow of gas-air 
mixture through the firecheck after a 
flashback has occurred. The valve shall be 
located up stream as close as practical to the 
irilet of the automatic firecheck. 

Caution: 

These valves shall not be reopened after a 
flashback has occurred until the firecheck has 
cooled sufficiently to prevent reignition of the 
flammable mixture and has been reset properly. 

(C) A safety blowout or backfiring preventer 
shall be provided in the mixture line near 
the outlet of each gas-mixing machine where 
the size of the piping is larger than 2-1/2 inches 
NPS, or equivalent, to protect the mixing 
equipment in the event of an explosion 
passing through an automatic firecheck. The 
manufacturer's instructions shall be 
followed when installing these devices, 
particularly after a disc has burst. The 
discharge from the safety blowout or 
backfire preventer shall be located or 
shielded so that particles from the ruptured 
disc cannot be directed toward personnel. 
Wherever there are intercoiinected installa- 
tions of gas-mixing machines with safety 
blowouts or backfire preventers, provision 
shall be made to keep the mixture from 
other machines from reaching any ruptured 
disc opening. Check valves shall not be used 
for this purpose. 

(D) Large-capacity premix systems provided 
with explosion heads (rupture discs) to 
relieve excessive pressure in pipelines shall 
be located at and vented to a safe outdoor 
location. Provisions shall be provided for 



215 



1311.12-1311.16 



2007 CALIFORNIA MECHANICAL CODE 



automatically shutting off the supply of gas- 
air mixture in the event of rupture. 

1311.13 Electrical Bonding and Grounding. 

(A) Each aboveground portion of a gas piping 
system that is likely to become energized shall 
be electrically continuous and bonded to an 
effective ground-fault current path. Gas piping 
shall be considered to be bonded when it is 
corinected to gas utilization equipment that is 
connected to the equipment groimding conductor 
of the circuit supplying that equipment. [NFPA 
54:7.13.1] 

(B) Gas piping shall not be used as a grounding 
conductor or electrode. [NFPA 54:7.13.2] 

1311.14 Electrical Circuits. Electrical circuits shall 
not utilize gas piping or components as conductors. 
[NFPA 54:7.14] 

Exception: Low-voltage (50 V or less) control 
circuits, ignition circuits, and electronic flame 
detection device circuits shall be permitted to 
make use of piping or components as a part of 
an electric circuit. 

1311.15 Electrical Connections. 

(A) All electrical connections between wiring and 
electrically operated control devices in a piping 
system shall conform to the requirements of 
NFPA 70, National Electrical Code. (See Section 
1311.13.) [NFPA 54:7.15.1] 

(B) Any essential safety control depending on 
electric current as the operating meditim shall be 
of a type that will shut off (fail safe) the flow of 
gas in the event of current failure. 

[NFPA 54:7.15.2] 

1311.16 Pipe Sizing Methods. 

1 31 1 .1 6.1 Where the pipe size is to be determined 
using any of the methods in Sections 1311.16.1.1 
through 1311.16.1.3, the diameter of each pipe 
segment shall be obtained from the pipe sizing 
tables in Section 1311.16.2 or from the sizing 
equations in Section 1311.16.3. [NFPA 54:6.1] 

1311.16.1.1 Longest Length IVIethod. The 

pipe size of each section of gas piping shall 
be determined using the longest length of 
piping from the point of delivery to the 
most remote outlet and the load of the 
section. [NFPA 54:6.1.1] 

1311.16.1.2 Branch Length Method. Pipe 
shall be sized as follows: [NFPA 54:6.1.2] 

(A) The pipe size of each section of the 
longest pipe run from the point of 
delivery to the most remote outlet shall 
be determined using the longest run of 
piping and the load of the section. 

(B) The pipe size of each section of branch 
piping not previously sized shall be 



determined using the length of piping 
from the point of delivery to the most 
remote outlet in each branch and the 
load of the section. 

1311.16.1.3 Hybrid Pressure. The pipe size 
for each section of higher pressure gas 
piping shall be determined using the longest 
length of piping from the point of delivery 
to the most remote line pressure regulator. 
The pipe size from the line pressure 
regulator to each outlet shall be determined 
using the length of piping from the 
regulator to the most remote outlet served 
by the regulator. [NFPA 54:6.1.3] 

1311.16.2 Tables for Sizing Gas Piping 
Systems. Tables 13-7 through 13-23 shall be 
used to size gas piping in conjunction with one 
of the methods described in Sections 1311.16.1.1 
through 1311.16.1.3. [NFPA 54:6.2] 

1311.16.3 Sizing Equations. The inside 
diameter of smooth wall pipe or tubing shall be 
determined by the sizing equations 13-1 and 13- 
2, using the equivalent pipe length determined 
by methods in Sections 1311.16.1.1 through 
1311.16.1.3. [NFPA 54:6.4] 

Equation 13-1 Low-Pressure Gas Formula [Less 
than 1.5 psi (10.3 kPa)] [NFPA 54:6.4.1] 



D=- 



Q0.3 



19.17 



/ AH \ o-^oe 
\ Crxl/ 



WHERE: 

D = inside diameter of pipe, in. 

Q = input rate appliance(s), cubic feet per hour at 
60°F (16°C) and 30 in. (759 mm) mercury column 

Pi = upstream pressure, psia (Pj + 14.7) 

P2 = downstream pressure, psia (P2 + 14.7) 

L = equivalent length of pipe, ft. 

D = pressure drop, in. water column (27.7 in. H2O =1 psi) 

Cr and Y in accordance with Table 13-4 

Equation 13-2 High-Pressure Gas Formula [1.5 
psi (10.3 kPa) and above] [NFPA 54:6.4.2] 



D= 



Q° 



,981 



18.93 



L CrxL J 



0.206 



216 



FUEL GAS PIPING 



Table 13-4 -1312.3 



WHERE: 

D = inside diameter of pipe, in. 

Q = input rate of appliance(s). 

Pj = upstream pressure, psia (Pj + 14.7). 

P2 = downstream pressure, psia (P2 + 14.7). 

L = equivalent length of pipe, ft. 

AH = presstire drop, in., water column (27.7 in. H2O = 1 psi). 

Q and Y in accordance with Table 13-4. 

TABLE 13-4 

Cr and Y for Natural Gas and Undiluted Propane 
at Standard Conditions [NFFA 54:6.4.2] 



Gas 


Formula Factors 
Cr Y 


Natural Gas 


0.6094 0.9992 


Undiluted Propane 


1.2462 0.9910 



For SI units: 1 i^= 0.028 m'; 1 ft. = 0.305 m; 1 in. water 
column = 0.249 kPa; 1 psi = 6.894 kPa; 1000 Btu/h = 
0.293 kW. 

1312.0 Equipment Connections to Building Piping. 

1312.1 Connecting Gas Equipment. Gas utilization 
eqiiipment shall be connected to the building piping 
in compliance with Sections 1312.4 through 1312.5 by 
one of the following: [NFFA 54:9.6.1] 

(1) Rigid metallic pipe and fittings. 

(2) Semirigid metallic tubing and metallic 
fittings. Aluminum aUoy tubing shaU not be 
used in exterior locations. 

(3) Listed flexible gas connectors in compliance 
with ANSI Z21.24, Standard for Connectors 
for Gas Appliances. The coimectors shall be 
used in accordance with the terms of their 
listing that are completely in the same 
room as the equipment. 

(4) CSST, where installed in accordance with the 
manufacturer's instructions. 

(5) Listed nonmetallic gas hose connectors in 
accordance with Section 1312.2. 

(6) Gas-fired food service (commercial cooking) 
equipment listed for use with casters or 
otherwise subject to movement for cleaning, 
and other large and heavy gas utiliza- 
tion equipment that can be moved, shall be 
connected in accordance with the connector 
manufacturer's installation instructions 
using a listed appliance connector complying 
with ANSI Z21.69, Standard for Connectors 
for Movable Gas Appliances. [NFFA 
54:9.6.1.1] 



(7) In 1312.1(2), (3), and (5), the connector or 
tubing shall be installed so as to be 
protected against physical and thermal 
damage. Aluminum alloy tubing and con- 
nectors shall be coated to protect against 
external corrosion where they are in contact 
with masonry, plaster, or insulation, or are 
subject to repeated wettings by such liquids 
as water (except rainwater), detergents, or 
sewage. 

1312.2 Use of Nonmetallic Gas Hose Connectors. 

Listed nonmetallic gas hose connectors shall be used 
in accordance with the terms of their listing and as 
follows: [NFFA 54:9.6.2] 

(A) Indoor. Indoor gas hose connectors shall be used 
only to connect laboratory, shop, and ironing 
equipment requiring mobility during operation. 
An equipment shutoff valve shall be installed 
where the connector is attached to the building 
piping. The connector shall be of minimum 
length and shall not exceed six (6) feet (1.8 m). The 
connector shall not be concealed and shall not 
extend from one room to another or pass 
through wall partitions, ceilings, or floors. 

(B) Outdoor. Outdoor gas hose connectors are 
permitted to connect portable outdoor gas-fired 
equipment. An equipment shutoff valve, a listed 
quick-disconnect device, or a listed gas 
convenience outlet shall be installed where the 
connector is attached to the supply piping and in 
such a manner to prevent the accumulation of 
water or foreign matter. This connection shall 
only be made in the outdoor area where the 
equipment is to be used. The cormector length 
shall not exceed fifteen (15) feest (4.6 m). 

1312.3 Connection of Portable and IVIobiie 
Industrial Gas Equipment. 

(A) Where portable industrial gas utilization 
equipment or equipment requiring mobility or 
subject to vibration is connected to the building 
gas piping system by the use of a flexible hose, 
the hose shall be suitable and safe for the 
conditions under which it can be used. [NFFA 
54:9.6.3.1] 

(B) Where industrial gas utilization equipment 
requiring mobility is connected to the rigid 
piping by the use of swivel joints or couplings, 
the swivel joints or couplings shall be suitable for 
the service required, and only the minimum number 
required shall be installed. [NFPA 54:9.6.3.2] 

(C) Where industrial gas utilization equipment 
subject to vibration is connected to the building 
piping system by the use of all metal flexible 
connectors, the connectors shall be suitable for 
the service required. [NFPA 54:9.6.3.2] 



217 



1312.3-1314.1 



2007 CALIFORNIA MECHANICAL CODE 



(D) Where flexible connections are used, they shall 
be of the minimum practical length and shall not 
extend from one room to another or pass 
through any walls, partitions, ceilings, or floors. 
Flexible connections shall not be used in any 
concealed location. They shall be protected 
against physical or thermal damage and shall be 
provided with gas shutoff valves in readily 
accessible locations in rigid piping upstream 
from the flexible connections. [NFPA 54:9.6.3.4] 

1312.4 Equipment Shutoff Valves and Connections. 

Gas utilization equipment connected to a piping 
system shall have an accessible, approved manual 
shutoff valve with a nondisplaceable valve member 
or a listed gas convenience outlet [NFPA 54:9.6.4] 
installed within six (6) feet (1.8m) of ttie eqtiipment it 
serves. Where a connector is used, the valve shall be 
installed up-stream of the connector. A union or 
flanged connection shall be provided downstream 
from this valve to permit removal of controls. 
Shutoff valves serving decorative gas appliances 
shall be permitted to be installed in fireplaces if 
Hsted for such use. [NFPA 54:9.6.4] 

Exceptions: 

(1) Shutoff valves may be accessibly located 
inside or under an appliance when such 
appliance can be removed without removal 
of the shutoff valve. 

(2) Shutoff valves may be accessibly located 
inside wall heaters and wall furnaces listed 
for recessed installation where necessary 
maintenance can be performed without 
removal of the shutoff valve. 

1312.5 Quick-Disconnect Devices. Quick-disconnect 
devices used to cormect equipment to flie building 
piping shall be listed. Where installed indoors, an 
approved manual shutoff valve with a nondisplace- 
able valve member shall be installed upstream of the 
quick-disconnect device. [NFPA 54:9.6.5] 

1312.6 Support of Cliimneys. All portions of 
chimneys shall be supported for ttie design and weight 
of the materials employed. Listed factory-built 
chimneys shall be supported and spaced in accordance 
with their listings and the manufacturers' instructions. 

1312.7 Sediment Trap. Where a sediment trap is not 
incorporated as a part of the gas utilization 
eqtiipment, a sediment trap shall be installed as close 
to the inlet of the equipment as practical at the time of 
equipment installation. The sediment trap shall be 
either a tee fitting with a capped nipple in tike bottom 
outlet as illustrated in Figure 13-1 or other device 
recogiuzed as an effective sediment trap. Illimiinating 
appliances, ranges, clothes dryers, decorative vented 
appliances for installation in vented fireplaces, gas 
fireplaces, and outdoor grills shall not be required to 
be so equipped. [NFPA 54:9.6.7] 



Gas supply inlet 



To 

equipment - 
Inlet 



-Tee fitting 



Nipple - 
Cap- 



3 In. (80 mm) 
minimum 



FIGURE 13-1 IVIethod of Installing a Tee Fitting 
Sediment Trap. 

1312.8 Installation of Piping. Piping shall be 
installed in a manner not to interfere with inspection, 
maintenance, or servicing of the gas utilization 
equipment. [NFPA 54:9.6.8] 

1313.0 Liquefied Petroleum Gas Facilities and 
Piping. Liquefied petroleum gas facilities shall comply 
with NFPA 58, Liquefied Petroleum Gas Code. 

1314.0 Pressure Testing and Inspection. 

1314.1 General. 

1 31 4.1 .1 Prior to acceptance and initial operation, 
all piping installations shall be inspected and 
pressure-tested to determine that the materials, 
design, fabrication, and installation practices 
comply with the requirements of this code. 
[NFPA 54:8.1.1.1] 

1314.1.2 Inspection shall consist of visual 
examination during or after manufacture, 
fabrication, assembly, or pressure tests as 
appropriate. Supplementary types of non- 
destructive inspection techniques, sudi as magnetic- 
particle, radiographic, and iiltrasonic, shall not be 
required unless specifically listed herein or in the 
engineering design. [NFPA 54:8.1.1.2] 

1314.1.3 Where repairs or additions are made 
following the pressure test, the affected piping 
shall be tested. Minor repairs and additions are 
not required to be presstire-tested provided that 
the work is inspected and connections are tested 
witih a noncorrosive leak-detecting fluid or other 
leak-detecting methods approved by the 
Authority Having Jurisdiction. [NFPA 54:8.1.1.3] 

1314.1.4 Where new branches are installed from 
the point of delivery to new appliance(s), only the 
newly installed branch(es) shall be required to be 
pressure-tested. Connections between the new 
piping and the existing piping shall be tested with 
a noncorrosive leak-detecting fluid or approved 
leak-detecting methods. [NFPA 54:8.1.1.4] 



218 



FUEL GAS PIPING 



1314.1-1314.6 



1314.1.5 A piping system shall be tested as a 
complete unit or in sections. Under no 
circumstances shall a valve in a line be used as a 
bulkhead between gas in one section of the 
piping system and test medium in an adjacent 
section imless two valves are installed in series 
with a valved "tell tale" located between these 
valves. A valve shall not be subjected to the test 
pressure unless it can be determined that the 
valve, including the valve-closing mechanism, is 
designed to safely withstand the pressure. 
[NFPA 54:8.1.1.5] 

1314.1.6 Regulator and valve assemblies 
fabricated independently of the piping system in 
which they are to be installed shall be permitted 
to be tested with inert gas or air at the time of 
fabrication. [NFPA 54:8.1.1.6] 

1314.1.7 Test Medium. The test medium shall 
be air, nitrogen, carbon dioxide, or an inert gas. 
OXYGEN SHALL NEVER BE USED. [NFPA 
54:8.1.2] 

1314.2 RESERVED. 

1314.3 Test Preparation. 

1314.3.1 Pipe joints, including welds, shall be 
left exposed for examination during the test. 
[NFPA 54:8.1.3.1] 

Exception: Covered or concealed pipe end 
joints that have been previously tested in 
accordance with this code. 

1 31 4.3.2 Expai\sion joints shall be provided with 
temporary restraints, if required, for the 
additional thrust load under test. [NFPA 
54:8.1.3.2] 

1314.3.3 Appliances and equipment that are not 
to be included in the test shall be either 
disconnected from the piping or isolated by 
blanks, blind flanges, or caps. Flanged joints at 
which blinds are inserted to blank off other 
equipment during the test shall not be required 
to be tested. [NFPA 54:8.1.3.3] 

1314.3.4 Where the piping system is connected 
to appliances, equipment, or equipment 
components designed for operating pressures of 
less than the test pressure, such appliances, 

. equipment, or equipment components shall be 
isolated from the piping system by disconnecting 
them and capping the outlet(s). [NFPA 54:8.1.3.4] 

1 31 4.3.5 Where the piping system is connected to 
appliances, equipment, or equipment components 
designed for operating pressures equal to or 
greater than the test pressure, such appliances and 
equipment shall be isolated from the piping 
system by closing the individual appliance 
equipment shutoff valve(s). [NFPA 54:8.1.3.5] 

1 31 4.3.6 All testing of piping systems shall be 
done with due regard for tihe safety of employees 

., and the public during the test. Bulkheads, 

/ arvchorage, and bracing suitably designed to resist 

test j^ressxires shall be installed if necessary. Prior 



to testing, the interior of the pipe shall be cleared of 
all foreign material. [NFPA 54:8.1.3.6] 

1314.4 Test Pressure. 

1314.4.1 Test pressure shall be measured with a 
manometer or with a pressure-measuring device 
designed and calibrated to read, record, or 
indicate a pressure loss due to leakage during 
the pressure test period. The source of pressure 
shall be isolated before the pressure tests are 
made. Mechanical gauges used to measure test 
pressures shall have a range such that the 
highest end of the scale is not greater than five 
times the test pressure. [NFPA 54:8.1.4.1] 

1 31 4.4.2 The test pressure to be used shall be no 
less than 1-1/2 times the proposed maximum 
working pressure, but not less than three (3) psi 
(20 kPa), irrespective of design pressure. [NFPA 
54:8.1.4.2] 

1314.1.4.3 Test duration shall be not less than 
one-half (1/2) hour for each 500 ft.^ (14 m^) of 
pipe volume or fraction thereof. When testing a 
system having a volume less than 10 ft.^ (0.28 m^) 
or a system in a single-family dwelling, the test 
duration shall be a minimiun of ten (10) minutes. 
The duration of the test shall not be required to 
exceed twenty-four (24) hours. [NFPA 54:8.1.4.3] 

1314.5 Detection of Leaks and Defects. 

1314.5.1 The piping system shall withstand the 
test pressure specified without showing any 
evidence of leakage or other defects. Any 
reduction of test pressures, as indicated by 
pressure gauges, shall be deemed to indicate the 
presence of a leak unless such reduction can be 
readily attributed to some other cause. [NFPA 
54:81.5.1] 

1314.5.2 The leakage shall be located by means 
of an approved gas detector, a noncorrosive leak 
detection fluid, or other approved leak detection 
methods. Matches, candles, open flames, or 
other methods that provide a source of igrution 
shaU not be used. [NFPA 54:8.1.5.2] 

1314.5.3 Where leakage or other defects are 
located, the affected portion of the piping system 
shall be repaired or replaced and retested. (See 
Section 1314.1.3.) [NFPA 54:8.1.5.3] 

1314.6 System and Equipment Leakage Test. 

1314.6.1 Test Gases. Leak checks using fuel 
gas shall be permitted in piping systems that 
have been pressure-tested in accordance with 
Section 1314.0. [NFPA 54:8.2.1] 

1314.6.2 Before Turning Gas On. Before gas is 
introduced into a system of new gas piping, the 
entire system shall be inspected to determine 
that there are no open fittings or ends and that 
all valves at unused outlets are closed and 
plugged or capped. [NFPA 54:8.2.2] 

1314.6.3 Test for Leakage. Immediately after 



219 



1314.6-1316.1 



2007 CALIFORNIA MECHANICAL CODE 



the gas is turned on into a new system or into a 
system that has been initially restored after an 
interruption of service, the piping system shall 
be checked for leakage. Where leakage is 
indicated, the gas supply shaU be shut off until 
the necessary repairs have been made. [NFPA 
54:8.2.3] 

1314.6.4 Placing Equipment in Operation. Gas 

utilization equipment shall not be placed in 
operation until after the piping system has been 
tested in accordance with Section 1314.6.3 and 
purged in accordance with Section 1314.7.2. 
[NFPA 54:8.2.4] 

1314.7 Purging. 

1314.7.1 Removal from Service. When gas 
piping is to be opened for servicing, addition, or 
modification, the section to be worked on shall 
be turned off from the gas supply at the nearest 
convenient point, and the line pressure vented to 
the outdoors or to ventilated areas of sufficient 
size to prevent accumulation of flammable 
mixtures. The remaining gas in this section of 
pipe shall be displaced with an inert gas as 
required by Table 13-5. [NFPA 54:8.3.1] 
TABLE 13-5 

Length of Piping Requiring Purging withi Inert 
Gas for Servicing or Modification 

[NFPA 54: Table 8.3.1] 



Nominal Pipe 
Size (in.) 



Length of Piping 
Requiring Purging (ft.) 



2-1/2 
3 



8 or larger 



>50 
>30 
>15 
>10 
Any length 



Note: For SI units: 1 ft. = 0.305 m. 

1314.7.2 Placing in Operation. When piping full 
of air is placed in operation, the air in the piping 
shall be displaced with fuel gas, except where 
such piping is required by Table 13-6 to be 
purged with an inert gas prior to introduction of 
fuel gas. The air can be safely displaced with fuel 
gas provided that a moderately rapid and 
continuous flow of fuel gas is introduced at one 
end of the line and air is vented out at the other 
end. The fuel-gas flow shall be continued without 
interruption until the vented gas is free of air. The 
point of discharge shall not be left xmattended 
during purging. After purging, the vent shall then 
be closed. Where required by Table 13-6, the air in 
the piping shall first be displaced with an inert 



gas, and the inert gas shall then be displaced with 
fuel gas. [NFPA 54:8.3.2] 

TABLE 13-6 

Length of Piping Requiring Purging with Inert 
Gas Before Placing in Operation 

[NFPA 54:Table 8.3.2] 

Nominal Pipe Length of Piping Requiring 

Size (in.) Purging (ft.) 



>30 
>15 
>10 



8 or larger 



Any length 



Note: For SI units: 1 ft. = 0.305 m. 

1314.7.3 Discharge of Purged Gases. The 

open end of piping systems being purged shall 
not discharge into confined spaces or areas 
where there are sources of ignition unless 
precautions are taken to perform this operation 
in a safe manner by ventilation of the space, 
control of purging rate, and elimination of all 
hazardous conditions. [NFPA 54:8.3.3] 

1314.7.4 Placing Equipment in Operation. 

After the piping has been placed in operation, all 
equipment shall be purged and then placed in 
operation, as necessary. [NFPA 54:8.3.4] 

1315.0 Interconnections between Gas-Piping 
Systems. [NFPA 54:5.3] 

1315.1 Interconnections Supplying Separate 
Users. Where two or more meters, or two or more 
service regulators where meters are not provided, 
are located on the same premises and supply 
separate users, the gas piping systems shall not be 
intercormected on the outlet side of the meters or 
service regulators. [NFPA 54:5.3.1] 

1315.2 Interconnections for Standby Fuels. Where 
supplementary gas for standby use is connected 
downstream from a meter, or a service regulator 
where a meter is not provided, a device to prevent 
backflow shall be installed. A three-way valve 
installed to admit the standby supply and at the same 
time shut off the regular supply shall be permitted to 
be used for this pturpose. [NFPA 54:5.3.2.2] 

1316.0 Required Gas Supply. 

1316.1 The following regtilations, as set forth in this 
section and in Section 1317.0, shall be the standard for 
the installation of gas piping. All natural gas 
regulations and tables are based on the use of gas 



220 



FUEL GAS PIPING 



1316.1-1317.4 



having a specific gravity of 0.60, supplied at six (6) to 
eight (8) inches (152-203 mm) water column pressure 
at the outlet of the meter. For undiluted liquefied 
petroleum gas, gas piping may be sized for 2,500 Btu 
per cubic foot (25.9 Watt-hours/L) at eleven (11) inches 
(279 mm) water column and specific gravity of 1.52. 

Note: 

Where gas of a different specific gravity is to be 
delivered, the serving gas supplier should be 
contacted for specific gravity conversion factors 
to use in sizing piping systems from the pipe 
sizing tables in this chapter. 

1316.2 The hourly volume of gas required at each 
piping outlet shall be taken as not less than the 
maximum hourly rating as specified by the 
manufacturer of the appliance or appliances to be 
connected to each such outlet. 

1 31 6.3 Where the gas appliances to be installed have not 
been definitely specified. Table 13-1 may be used as a 
reference to estimate requirements of typical appliances. 

1 31 6.3.1 To obtain the cubic feet per hour (L/sec.) 
of gas required, divide the input of the appliances 
by the average Btu (W) heating value per cubic 
foot (L) of the gas. The average Btu (W) per cubic 
foot (L) of the gas in the area of the installation 
may be obtained from the serving gas supplier. 

1316.4 The size of the supply piping outlet for any 
gas appliance shall not be less than 1/2 inch (15 mm). 

1316.5 The minimum size of any piping outlet for a 
mobile home shall be 3/4 inch (20 mm). 

1317.0 Required Gas Piping Size. 

1317.1 Where the maximum demand does not 
exceed 250 cubic feet per hour (2 L/sec.) and the 
maximum length of piping between the meter and 
the most distant outlet is not over 250 feet (76,200 
mm), the size of each section and each outlet of any 
system of gas piping shall be determined by means 
of Table 13-7 for steel pipe. Table 13-15 for copper 
tubing systems, or Table 13-19 for CSST systems. 
Other systems within the range of Tables 13-7, 13-15, 
or 13-19 may be sized from that table or by means of 
the methods set forth in Section 1317.3. 

1317.2 To determine the size of each section of pipe 
in any system within the range of Table 13-7, 
proceed as follows: 

(1) Measure the length of the pipe from the gas 
meter location to the most remote outlet on the 
system. 

(2) In Table 13-7 select the length in feet column and 
row showing that distance, or the next longer 
distance ,if the table does not give the exact length. 

(3) Starting at the most remote outlet, find in the 



row just selected the gas demand for that outlet. 
If the exact figtire of demand is not sown, choose 
the next larger figure in the row. 

(4) At the top of column in Table 12-13 will be 
found the correct size of pipe. 

(5) Using this same row, proceed in a similar 
manner for each section of pipe serving this 
outlet. For each section of pipe, determine the 
total gas demand supplied by that section. 
Where gas piping sections serve both heating 
and cooling equipment and the installation 
prevents both units from operating simultaneously, 
only the larger of the two demand loads need be 
used in sizing these sections. 

(6) Size each section of branch piping not 
previously sized by measuring the distance from 
the gas meter location to the most remote outlet 
in that branch and follow the procedures of 
steps 2, 3, 4, and 5 above. 

Note: 

Size branch piping sections in the order of their 
distance from the meter location, beginning with the 
most distant outlet not previously sized. 

1317.3 For conditions other than those covered by 
Section 1317.1, such as longer runs or greater gas 
demands, the size of each gas piping system shall be 
determined by standard engineering methods 
acceptable to the Authority Having Jurisdiction. 
Each such system shall be so designed that the total 
pressure drop between the meter or other point of 
supply and any outlet when full demand is being 
supplied to all outlets will at no time exceed 0.5 
inches (12.7 mm) water coltimn pressure. 

1317.4 Where the gas pressure may be higher than 
fourteen (14) inches (356 mm) or lower than six (6) 
inches (152 mm) of water column, or when diversity 
demand factors are used, the design, pipe, sizing, 
materials, location, and use of such systems first 
shall be approved by the Authority Having 
Jurisdiction. Piping systems designed for pressures 
higher than the serving gas supplier's standard 
delivery pressure shall have prior verification from 
the gas supplier of the availability of the design 
pressure. Systems using undiluted liquefied 
petroleum gas may be sized using Table 13-11 for 
steel pipe and Table 13-23 for CSST for eleven (11) 
inches (279 mm) water column and in accordance 
with the provisions of Sections 1317.1 and 1317.2. For 
copper tubing systems using undiluted liquefied 
petroleum gas, the capacity of the tubing shall be 
determined by multiplying the values of Table 13-15 
by the appropriate factor from Table 13-16. 



221 



2007 CALIFORNIA MECHANICAL CODE 

FIGURE 13-2 Example Illustrating Use of Tables 13-1 and 13-7 

Problem: Determine the reqxiired pipe size of each section and outlet of the piping system shown in Figure 13-2. Gas 
to be used has a specific gravity of 0.60 and 1,100 Btu per cubic foot (11.4 Watt-Hour/L), delivered at eight (8) inch 
(203 mm) water column pressure. 











150,000 Btu/lir 








• (43,950 W) 








Furnace 








30 gallon (113.61) 






o 


Automatic 






c 


'-■ Water Heater 






H 
r- 








^ 


3 - 5 


J~. 






D 




03 
O 




Section 3 




Section 2 Section 1 > 


3° 




20' 




10' 10' 


3_ 






-/6096 mm\ 




_(3048 mm)_(3048 mm)_ 


1 




^~ \^^\J%J\J H 11 I tj 




1 




1 






O 


Ul 




65 
O 






c 






*.. 






r" 


=k 


i 


3 




O 

c 


M^:: Gas 

3 - Refrigerator 


V 




O 


3, 


Gasr 


i/leter 






1 







Range 

Solution: 

(1) Maximum gas demand of outlet A — 

32 cubic feet per hour (0.21 L/sec.) (from Table 13-1). 
Maximum gas demand of outlet B — 

3 cubic feet per hour (0.02 L/sec.) (from Table 13-1). 
Maximum gas demand of outlet C — 

59 cubic feet per hour (0.46 L/sec.) (from Table 13-1). 
Maximtim gas demand of outlet D — 

136 cubic feet per hour (1.1 L/sec.) (150,000 Btu/hour [43,950 W]) 

divided by 1,100 Btu per cubic foot (11.4 Watt-Hour/L) 

(2) The length of pipe from the gas meter to the most remote outlet (outlet A) is 60 feet (18,288 mm). 

(3) Using the length in feet column row marked 60 feet (18,288 mm) in Table 13-7: 

Outlet A, supplying 32 cubic feet per hour (0.21 L/sec), requires 1/2 inch (15 nmi) pipe. Section 1, supplying 
outlets A and B, or 35 cubic feet per hour (0.24 L/sec.) reqxaires 1/2 inch (15 mm) pipe. 

Section 2, supplying outlets A, B, and C, or 94 cubic feet per hour (0.7 L/sec.) requires 3/4 inch (20 mm.) pipe. 

Section 3, supplying outlets A, B, C, and D, or 230 cubic feet per hour (1.8 L/sec), requires one (1) inch (25 mm) 
pipe. 

(4) Using the column marked 60 feet (18,288 mm) in Table 13-7 (no colimin for actual length of 55 feet (16,764 mm): 
Outlet B supplying 3 cubic feet per hour (0.02 L/sec), requires 1/2 inch (15 mm) pipe. 

Outlet C, supplying 59 cubic feet per hour (0.46 L/sec), requires 1/2 inch (15 mm) pipe. 

(5) Using the column marked 50 feet (15,240 mm) in Table 13-7: 

Outlet D, supplying 136 cubic feet per hour (1.1 L/sec), requires 3/4 inch (20 mm) pipe. 



222 



FUEL GAS PIPING 



Table 13-7 



Table 13-7 Schedule 40 Metallic Pipe [NFPA 54: Table 6.2(a)] 



Gas: 



Inlet Pressure: 



Pressure Drop; 



Specific Gravity: 



Natural 



Less than 2 psi 



0.3 in. w.c. 



0.60 



Pipe Size, inches 



Nominal: 


1/2 


3/4 


1 


1-1/4 


1-1/2 


2 


2-1/2 


3 


4 


5 


6 


8 


10 


12 


Actual ID: 


0.622 


0.824 


1.049 


1.380 


1.610 


2.067 


2.469 


3.068 


4.026 


5.047 


6.065 


7.981 


10.020 


11.938 


Length (ft) 












Capacit 


y in Cubic 


: Feet of G 


IS per Ho 


ir 










10 


131 


273 


514 


1,060 


1,580 


3,050 


4,860 


8,580 


17,500 


31,700 


51,300 


105,000 


191,000 


303,000 


20 


90 


188 


353 


726 


1,090 


2,090 


3,340 


5,900 


12,000 


21,800 


35,300 


72,400 


132,000 


208,000 


30 


72 


151 


284 


583 


873 


1,680 


2,680 


4,740 


9,660 


17,500 


28,300 


58,200 


106,000 


167,000 


40 


62 


129 


243 


499 


747 


1,440 


2,290 


4,050 


8,270 


15,000 


24,200 


49,800 


90,400 


143,000 


50 


55 


114 


215 


442 


662 


1,280 


2,030 


3,590 


7,330 


13,300 


21,500 


44,100 


80,100 


127,000 


60 


50 


104 


195 


400 


600 


1,160 


1,840 


3,260 


6,640 


12,000 


19,500 


40,000 


72,600 


115,000 


70 


46 


95 


179 


368 


552 . 


1,060 


1,690 


3,000 


6,110 


11,100 


17,900 


36,800 


66,800 


106,000 


80 


42 


89 


167 


343 


514 


989 


1,580 


2,790 


5,680 


10,300 


16,700 


34,200 


62,100 


98,400 


90 


40 


83 


157 


322 


482 


928 


1,480 


2,610 


5,330 


9,650 


15,600 


32,100 


58,300 


92,300 


100 


38 


79 


148 


304 


455 


877 


1,400 


2,470 


5,040 


9,110 


14,800 


30,300 


55,100 


87,200 


125 


33 


70 


131 


269 


403 


777 


1,240 


2,190 


4,460 


8,080 


13,100 


26,900 


48,800 


77,300 


150 


30 


63 


119 


244 


366 


704 


1,120 


1,980 


4,050 


7,320 


11,900 


24,300 


44,200 


70,000 


175 


28 


58 


109 


224 


336 


648 


1,030 


1,820 


3,720 


6,730 


10,900 


22,400 


40,700 


64,400 


200 


26 


54 


102 


209 


313 


602 


960 


1,700 


3,460 


6,260 


10,100 


20,800 


37,900 


59,900 


250 


23 


48 


90 


185 


277 


534 


851 


1,500 


3,070 


5,550 


8,990 


18,500 


33,500 


53,100 


300 


21 


43 


82 


168 


251 


484 


771 


1,360 


2,780 


5,030 


8,150 


16,700 


30,400 


48,100 


350 


19 


40 


75 


154 


231 


445 


709 


1,250 


2,560 


4,630 


7,490 


15,400 


28,000 


44,300 


400 


18 


37 


70 


143 


215 


414 


. 660 


1,170 


2,380 


4,310 


6,970 


14,300 


26,000 


41,200 


450 


17 


35 


66 


135 


202 


389 


619 


1,090 


2,230 


4,040 


6,540 


13,400 


24,400 


38,600 


500 


16 


33 


62 


127 


191 


367 


585 


1,030 


2,110 


3,820 


6,180 


12,700 


23,100 


36,500 


550 


15 


31 


59 


121 


181 


349 


, 556 


982 


2,000 


3,620 


5,870 


12,100 


21,900 


34,700 


600 


14 


30 


56 


115 


173 


333 


530 


937 


1,910 


3,460 


5,600 


11,500 


20,900 


33,100 


650 


14 


29 


54 


110 


165 


318 


508 


897 


1,830 


3,310 


5,360 


11,000 


20,000 


31,700 


700 


13 


27 


52 


106 


159 


306 


488 


862 


1,760 


3,180 


5,150 


10,600 


19,200 


30,400 


750 


13 


26 


50 


102 


153 


295 


470 


830 


1,690 


3,060 


4,960 


10,200 


18,500 


29,300 


800 


12 


26 


48 


99 


148 


285 


454 


802 


1,640 


2,960 


4,790 


9,840 


17,900 


28,300 


850 


12 


25 


46 


95 


143 


275 


439 


776 


1,580 


2,860 


4,640 


9,530 


17,300 


27,400 


900 


11 


24 


45 


93 


139 


267 


426 


752 


1,530 


2,780 


4,500 


9,240 


16,800 


26,600 


950 


11 


23 


44 


90 


135 


259 


413 


731 


1,490, 


2,700 


4,370 


8,970 


16,300 


25,800 


1,000 


11 


23 


43 


87 


131 . 


252 


402 


711 


1,450 


■ 2,620 


4,250 


8,720 


15,800 


25,100 


1,100 


10 


21 


40 


83 


124 


240 


382 


675 


1,380 


2,490 


4,030 


8,290 


15,100 


23,800 


1,200 


NA 


20 


39 


79 


119 


229 


364 


644 


1,310, 


2,380 


3,850 


7,910 


14,400 


22,700 


1,300 


NA 


20 


37 


76 


114 


219 


349 


617 


1,260 


2,280 


3,680 


7,570 


13,700 


21,800 


1,400 


NA 


19 


35 


, 73 


109 


210 


335 


592 


1,210; 


2,190 


3,540 


7,270 


13,200 


20,900 


1,500 


NA 


18 


34 


70 


105 


203 


323 


571 


1,160 


2,110 


3,410 


7,010 


12,700 


20,100 


1,600 


NA, 


18 


33 


68 


102 


196 


312 


551 


1,120 


2,030 


3,290 


6,770 


12,300 


19,500 


1,700 


NA 


17 


32 


66 


98 


189 


302 


533 


1,090 


1,970 


3,190 


6,550 


11,900 


18,800 


1,800 


NA 


16 


31 


64 


95 


184 


293 


517 


1,050 


1,910 


3,090 


6,350 


11,500 


18,300 


1,900 


NA 


16 


30 


62 


93 


178 


284 


502 


1,020 


1,850 


3,000 


6,170 


11,200 


17,700 


2,000 


NA 


16. 


29 


60 


90 ' 


173 


276 


488 


1,000 


1,800 


2,920 


6,000 


10,900 


17,200 



NA means a flow of less than 10 cfh. 

Note: All table entries are rounded to 3 significant digits. 



223 



Table 13-8 



2007 CALIFORNIA MECHANICAL CODE 



Table 13-8 Schedule 40 Metallic Pipe [NFPA 54: Table 6.2(b)] 

























Gas: 


Natural 




Inlet Pressure: 


Less than 2 


psi 




Pressure Drop: 


0.5 in. w.c. 




SpedHc Gravity: 


0.60 




Pipe Size (in.) 


Nominal: 


Vi 


»/i 


1 


1'/. 


IVj 


2 


VA 


3 


4 


5 


6 


8 


10 


12 


Actual ID: 


0.622 


0.824 


1.049 


1.380 


1.610 


2.067 


2.469 


3.068 


4.026 


5.047 


6.065 


7.981 


10.020 


11.938 


Length (ft) 












Capacit 


in Cubic Feet of Gas per Hour 










10 


172 


380 


678 


1,390 


2,090 


4,020 


6,400 


11,300 


23,100 


41,800 


67,600 


139,000 


2.52,000 


399,000 


20 


118 


247 


466 


957 


1,4.30 


2,760 


4,400 


7,780 


15,900 


28,700 


46,500 


95,.50O 


173,000 


275,000 


30 


95 


199 


374 


768 


1,160 


2,220 


3,530 


6,260 


12,700 


23,000 


37,300 


76,700 


139,000 


220,000 


40 


81 


170 


320 


657 


985 


1,900 


3,020 


5,350 


10,900 


19,700 


31,900 


65,600 


119,000 


189,000 


50 


72 


151 


284 


583 


873 


1,680 


2,680 


4,740 


9,6()0 


17,500 


28,300 


58,200 


106,000 


167,000 


60 


05 


137 


267 


528 


791 


1,520 


2,430 


4,290 


8,760 


15,800 


25,600 


52,700 


95,700 


162,000 


70 


00 


128 


2.37 


486 


728 


1,400 


2,230 


3,950 


8,050 


14,600 


23,600 


48,600 


88,100 


1.39,000 


80 


6S 


117 


220 


452 


677 


1,.100 


2,080 


3,670 


7,490 


13,600 


22,000 


45,100 


81,900 


130,000 


90 


62 


110 


207 


424 


(J36 


1.220 


1,950 


3,4.50 


7,030 


12,700 


20,600 


•12,300 


76,900 


122,000 


100 


50 


104 


196 


400 


800 


1,1 ()0 


1,840 


3,260 


6,640 


12,000 


19,500 


40,000 


72,600 


1 15,000 


125 


44 


92 


173 


3.55 


5.32 


1,020 


1,630 


2,890 


5,890 


10,60(1 


17,200 


35,400 


64,300 


102,000 


mo 


40 


83 


157 


322 


482 


928 


1.480 


2,610 


5,330 


9,650 


15,600 


32,100 


58,300 


92,300 


175 


37 


77 


144 


296 


443 


854 


1,.360 


2,410 


4,910 


8,880 


14,400 


29,500 


53,600 


84,900 


200 


34 


71 


134 


276 


412 


794 


1,270 


2,240 


4,660 


8,260 


13,400 


27,600 


49,900 


79,000 


250 


30 


83 


119 


244 


366 


704 


1,120 


1,980 


4,050 


7,320 


11,900 


24,300 


44,200 


70,000 


300 


27 


.57 


108 


221 


331 


638 


1,020 


1,800 


3,670 


6,630 


10,700 


22,100 


40,100 


63,400 


330 


25 


.53 


99 


203 


305 


587 


935 


1,650 


3,370 


6,100 


9,880 


20,300 


36,900 


58,400 


400 


2.3 


49 


92 


189 


283 


546 


870 


1,340 


3,140 


5,680 


9,190 


18,900 


34,300 


54,.300 


460 


22 


46 


86 


177 


266 


512 


816 


1,440 


2,940 


5,330 


8,620 


17,700 


32,200 


60,900 


600 


21 


43 


82 


168 


251 


484 


771 


1,380 


2,780 


5,030 


8,1,50 


16,700 


30,400 


■18,100 


650 


20 


41 


78 


li)9 


239 


459 


732 


1,290 


2,640 


4,780 


7,740 


16,900 


28,900 


46,700 


(500 


19 


39 


74 


152 


228 


438 


699 


1,240 


2,620 


4,660 


7,380 


16,200 


27,600 


43,600 


650 


18 


38 


71 


146 


218 


420 


6(i9 


1,180 


2,410 


4,3()0 


7,070 


14,300 


26,400 


41,800 


700 


17 


36 


68 


140 


209 


403 


643 


1,140 


2,320 


4,190 


0,790 


14,000 


2.5,300 


40,100 


750 


17 


35 


66 


1,36 


202 


389 


619 


1,090 


2,230 


4,040 


6,540 


13,400 


24,400 


38,600 


SOO 


16 


34 


63 


ISO 


196 


376 


598 


1,060 


2,160 


3,900 


6,320 


13,000 


23,600 


37,300 


860 


16 


33 


61 


126 


189 


363 


579 


1,020 


2,090 


.3,780 


6,110 


12,600 


22,800 


36,100 


900 


15 


32 


.59 


122 


183 


3.52 


.561 


992 


2,020 


3,660 


5,930 


12,200 


22,100 


35,000 


960 


15 


31 


58 


118 


178 


342 


545 


963 


1,960 


3,650 


5,760 


11,800 


21, .500 


34,000 


1,000 


14 


30 


56 


115 


173 


333 


530 


937 


1,910 


.3,460 


5,600 


n,.500 


20,900 


33,100 


1,100 


14 


28 


53 


109 


164 


316 


503 


890 


1,810 


3,280 


5,320 


10,900 


19,800 


31,400 


1,200 


1.3 


27 


51 


104 


156 


301 


480 


849 


1,730 


3,130 


5,070 


10,400 


18,900 


30,000 


1,300 


12 


26 


49 


100 


1.50 


289 


460 


813 


1,660 


3,000 


4,860 


9,980 


18,100 


28,700 


1,400 


12 


25 


47 


96 


144 


277 


442 


781 


1,590 


2,880 


4,670 


9,690 


17,400 


27,600 


1,500 


11 


24 


45 


93 


1.39 


2(i7 


426 


7.52 


1„5.30 


2,780 


4,500 


9,240 


l(i,800 


26,600 


1,600 


11 


23 


44 


89 


134 


258 


411 


727 


1,480 


2,()80 


4,340 


8,920 


16,200 


23,600 


1,700 


11 


22 


42 


86 


130 


260 


398 


708 


1,430 


2,!)90 


4,200 


8,(>30 


15,700 


24,800 


1,800 


10 


22 


41 


84 


126 


242 


386 


682 


1,390 


2,!i20 


4,070 


8,370 


13,200 


24,100 


1,900 


10 


21 


40 


81 


122 


235 


376 


662 


1,360 


2,440 


3,960 


8,130 


14,800 


23,400 


2,000 


N.\ 


20 


39 


79 


119 


229 


364 


644 


1,310 


2,380 


3,850 


7,910 


14,400 


22,700 



NA means a flow of less tlian 1 clh. 

Note: All table entries are roLinded to 3 significant digits. 



224 



FUEL GAS PIPING 



Table 13-9 



Table 13-9 Schedule 40 Metallic Pipe [NFPA 54: Table 6.2(c)] 















Gas: 


Natural 




Inlel Pressure: 


2.0 psi 




Pressure Drop: 


1.0 psi 




Specific Gravity: 


0.60 




Pipe Size (in.) 


Nominal: 


•/4 


'/i 


1 


\'A 


VA 


2 


VA 


3 


4 


Actual ID: 


0.622 


0.824 


1.049 


1.380 


1.610 


2.067 


2.469 


3.068 


4.026 


Length (ft) 








Capacity in 


Cubic Feet of Gas per Hour 








10 


1,510 


.3,040 


6,660 


11,400 


17,100 


32,900 


62,500 


92,800 


189,000 


20 


1,070 


2,150 


3,930 


8,070 


12,100 


23,300 


37,100 


65,600 


134,000 


30 


869 


1,760 


3,210 


6,590 


9,880 


19,000 


30,300 


63,600 


109,000 


40 


753 


1,520 


2,780 


.5,710 


8,550 


16,500 


26,800 


46,400 


94,700 


50 


078 


1,360 


2,490 


5,110 


7,660 


14,700 


23,600 


41,600 


84,700 


60 


615 


1,240 


2,270 


4,660 


6,980 


13,500 


21,400 


37,900 


77,300 


70 


609 


1,150 


2,100 


4,320 


6,470 


12,600 


19,900 


36,100 


71,000 


80 


532 


1,080 


1,970 


4,040 


6,050 


11,700 


18,600 


32,800 


67,000 


00 


502 


1,010 


1,860 


3,810 


5,700 


11,000 


17,600 


30,900 


63,100 


100 


462 


934 


1,710 


3,510 


r.,260 


10,100 


16,100 


28,.500 


58,200 


125 


414 


830 


1,680 


3,140 


4,700 


9,060 


14,400 


26,600 


.52,100 


150 


372 


751 


1,370 


2,820 


4,220 


8,130 


13,000 


22,900 


46,700 


175 


.344 


695 


1,270 


2,601 


3,910 


7,530 


12,000 


21,200 


43,300 


200 


318 


642 


1,170 


2,410 


.3,610 


6,960 


11,100 


19,600 


40,000 


250 


279 


683 


1,040 


2,140 


3,210 


6,180 


9,860 


17,400 


36,600 


300 


253 


528 


945 


1,940 


2,910 


.6,600 


8,920 


15,800 


32,200 . 


350 


232 


480 


869 


1,790 


2,670 


5,150 


8,210 


14.600 


29,600 


400 


216 


4fi2 


809 


1,660 


2,490 


4,790 


7,640 


13,500 


27,500 


450 


203 


424 


759 


1,600 


2,330 


4,600 


7,170 


12.700 


25,800 


600 


192 


401 


717 


1,470 


2,210 


4.250 


6,770 


12,000 


24,400 


550 


182 


381 


681 


1,400 


2,090 


4,030 


6,430 


11,400 


23,200 


600 


174 


363 


650 


1,330 


2,000 


3,850 


6,130 


10,800 


22,100 


1)50 


166 


348 


622 


1,280 


1,910 


3,680 


6,870 


10,400 


21,200 


700 


160 


334 


598 


1,230 


1,840 


3,540 


5,640 


9,970 


20,.300 


760 


1.54 


322 


576 


1,180 


1,770 


3,410 


5,440 


9,010 


19,000 


800 


149 


311 


566 


1,140 


1,710 


3,290 


6,250 


9,280 


18,900 


850 


144 


.301 


538 


1,100 


l,(i50 


3,190 


5,080 


8,980 


18,300 


900 


1.39 


292 


522 


1,070 


1,600 


3,090 


4,930 


8,710 


17,800 


960 


135 


283 


mi 


1,040 


1,560 


3,000 


4,780 


8,460 


17,200 


1,000 


132 


276 


493 


1,010 


1,520 


2,920 


4,650 


8,220 


16,800 


1,100 


125 


262 


468 


960 


1,440 


2,770 


4,420 


7,810 


16,900 


1,200 


119 


250 


446 


917 


1,370 


2,640 


4,220 


7,460 


15,200 


1,300 


114 


2.39 


427 


878 


1,320 


2,680 


4,040 


7,140 


14,600 


1,400 


110 


230 


411 


843 


1,260 


2,430 


3,880 


6,860 


14,000 


1,500 


106 


221 


.396 


812 


1.220 


2,340 


3,740 


6,600 


13,ri00 


1,000 


102 


214 


382 


784 


1,180 


2,200 


3,610 


6,880 


1,3,000 


1,700 


99 


207 


.370 


759 


1,140 


2,190 


3,490 


6,170 


12,600 


1,800 


96 


200 


358 


736 


1.100 


2,120 


3,390 


5,980 


12,200 


1,900 


93 


196 


348 


716 


1,070 


2,060 


3,290 


.5,810 


11,900 


2,000 


91 


189 


339 


695 


1,040 


2,010 


3,200 


5,650 


11,!'jOO 



Note: All table entries are rounded to 3 signiilcaiu digits. 



225 



Table 13-10 



2007 CALIFORNIA MECHANICAL CODE 



Table 13-10 Schedule 40 Metallic Pipe [NFPA 54: Table 6.2(d)l 















Cas: 


Natural 




Inlet Preasure; 


3.0 psi 




Pressure Drop; 


2.0 psi 




Specific Gravity: 


0.60 




Pipe Size (in.) 


Nominal; 


'A 


'A 


1 


VA 


VA 


2 


2V4 


3 


4 


Actual ID; 


0.622 


0.824 


1.049 


1.380 


1.610 


2.067 


2.469 


3.068 


4.026 


Length (ft) 








Capacity iu 


Cubic Feet of Gas per Hoiu: 








10 


2,350 


4,920 


9,270 


19,000 


28,500 


54,900 


87,500 


155,000 


316,000 


20 


1,620 


3,380 


6,370 


13,100 


19,600 


37,700 


60,100 


106,000 


217,000 


30 


1,300 


2,720 


5,110 


10,600 


15,700 


30,300 


48,300 


85,400 


174,000 


40 


1,110 


2,320 


4,380 


8,990 


13,600 


26,900 


41,300 


73,100 


149,000 


50 


985 


2,060 


3,880 


7,970 


11,900 


23,000 


36,600 


64,800 


132,000 


60 


892 


1,870 


3,520 


7,220 


10,800 


20,800 


33,200 


68,700 


120,000 


70 


821 


1,720 


3,2.30 


6,640 


9,950 


19,200 


30,500 


54,000 


1 10,000 


80 


704 


1,600 


3,010 


6,180 


9,260 


17,800 


28,400 


50,200 


102,000 


90 


717 


1,500 


2,820 


5,800 


8,680 


16,700 


26,700 


47,100 


96,100 


100 


677 


1,420 


2,670 


5,470 


8,200 


15,800 


25,200 


44,500 


90,800 


125 


600 


1,250 


2,300 


4,850 


7,270 


14,000 


22,300 


39,600 


80,600 


150 


544 


1,140 


2,140 


4,400 


6,!>90 


12,700 


20,200 


36,700 


72,900 


175 


500 


1,050 


1,970 


4,040 


6,060 


11,700 


18,600 


32,900 


67,100 


200 


4« 


978 


1,830 


3,760 


5,640 


10,900 


17,300 


30,600 


62,400 


250 


412 


882 


1,620 


3,330 


5,000 


9,620 


15,300 


27,100 


55,300 


300 


374 


781 


1,470 


3,020 


4,.530 


8,720 


13,900 


24,600 


50,100 


350 


344 


719 


l,3.'i0 


2,780 


4,170 


8,020 


12,800 


22,600 


46,100 


"100 


320 


669 


1,260 


2,590 


3,870 


7,460 


11,900 


21,000 


42,900 


450 


300 


627 


1,180 


2,430 


3,640 


7,000 


11,200 


19,700 


40,200 


500 


283 


593 


1,120 


2,290 


3,430 


6,610 


10,S>00 


18,600 


38,000 


550 


269 


663 


l,0(iO 


2,180 


3,260 


6,280 


10,000 


17,700 


36,100 


600 


257 


537 


1,010 


2,080 


3,110 


5,990 


9,6!!0 


16,900 


34,400 


650 


246 


514 


909 


1.990 


2,980 


5,740 


9,150 


16,200 


33,000 


700 


230 


494 


931 


1,910 


2,860 


5,510 


8,790 


16,600 


31,700 


750 


228 


476 


897 


1,840 


2,760 


i),310 


8,470 


15,000 


30,500 


800 


220 


460 


860 


1,780 


2,660 


5,130 


8,180 


14,500 


29,600 


850 


213 


445 


838 


1,720 


2,580 


4,960 


7,910 


14,000 


28,600 


900 


206 


431 


812 


1,670 


2,600 


4,810 


7,670 


13.600 


27,700 


950 


200 


419 


789 


1,620 


2,480 


4,670 


7,450 


13,200 


26,900 


1,000 


196 


407 


767 


1,580 


2,300 


4,550 


7,240 


12,800 


26,100 


1,100 


185 


387 


729 


1,500 


2,240 


4,320 


6,890 


12,200 


24,800 


1,200 


177 


369 


695 


1,4.30 


2,140 


4,120 


6,570 


11,600 


23,700 


1,800 


169 


S58 


666 


1,370 


2,060 


3,940 


6,290 


11,100 


22,700 


1,400 


1()2 


340 


640 


1,310 


1,970 


3,790 


6,040 


10,700 


21,800 


1,500 


166 


327 


610 


1,270 


1,900 


3,650 


5,820 


10,300 


21,000 


1,600 


161 


316 


i>95 


1,220 


1,830 


3,530 


6,620 


10,000 


20,300 


1,700 


146 


306 


576 


1,180 


1,770 


3,410 


5,440 


9,610 


19,600 


1,800 


142 


296 


5.58 


1,160 


1,720 


3,310 


5,270 


9,320 


19,000 


1,900 


138 


288 


642 


1,110 


1,670 


3,210 


5,120 


9,060 


18,400 


2,000 


134 


280 


527 


1,080 


1,620 


3,120 


4,980 


8,800 


18,000 



Note: All table entries are roundeti to 3 significant digits. 



226 



FUEL GAS PIPING 



Table 13-11 



Table 13-11 Schedule 40 Metallic Pipe [NFPA 54: Table 6.2()] 















Gasi 


Natiffal 




Inlet Prcssiu-e: 


5,0 psi 




Pressure Drop; 


3.6 psi 




Specific Gravity; 


0.60 




Pipe Size (in.) 


Nominal; 


'A 


'A 


1 


VA 


VA 


2 


'i'A 


3 


4 


Actual ID: 


0.622 


0.824 


1.049 


1.380 


1.610 


2.067 


2.469 


3.068 


4.026 


Length (ft) 








Capacity in 


Cubic Feet of Gas per Hour 








10 


3,190 


6,430 


11,800 


24,200 


30,200 


69.700 


111,000 


196,000 


401,000 


20 


2,250 


4,550 


8,320 


17,100 


25,600 


49.300 


78,600 


139,000 


283,000 


30 


1,840 


3,720 


6,790 


14,000 


20,900 


40,300 


64,200 


113,000 


231,000 


-10 


1,590 


3,220 


5,880 


12,100 


18,100 


34,900 


55,600 


98.200 


200,000 


SO 


1,430 


2,880 


5,260 


10,SOO 


16,200 


31,200 


49,700 


87,900 


179,000 


60 


1,300 


2,030 


4,800 


9,860 


14,800 


28,500 


45,400 


80,200 


164,000 


70 


1,200 


2,430 


4,450 


9,130 


13,700 


26,400 


42,000 


74,300 


151,000 


80 


1,150 


2,330 


4,260 


8,640 


12,800 


24,700 


39,300 


69,500 


142,000 


90 


1,060 


2,150 


3,920 


8,050 


12,100 


23.200 


37,000 


65,500 


134,000 


100 


979 


1,980 


.3,620 


7,430 


11,100 


21,400 


34,200 


60.400 


123,000 


125 


876 


1,770 


3,240 


6,640 


9,9S0 


19,200 


30,600 


54.000 


110,000 


150 


785 


1,590 


2,910 


5,960 


8,940 


17,200 


27,400 


48,500 


98,900 


175 


728 


1,470 


2,690 


.5,520 


8,270 


15,900 


25,400 


44,900 


91,000 


200 


673 


^.WO 


2.490 


6,100 


7,650 


14,700 


23,500 


41,500 


84.700 


250 


558 


1,170 


2,200 


4,510 


6,760 


13.000 


20,800 


36,700 


74,900 


300 


506 


1,060 


1,900 


4,090 ' 


6.130 


11.800 


18,800 


33,300 


67,800 


350 


465 


973 


1,830 


3.760 


6,64.0 


10,900 


17,.300 


30.600 


()2,400 


400 


433 


905 


1,710 


3,500 


5,250 


10.100 


16,100 


28.600 


58,100 


•150 


406 


849 


1,600 


3,290 


4,920 


9,480 


15,100 


26,700 


54,500 


500 


384 


802 


1,510 


3.100 


4,650 


8.950 


14,300 


25,200 


51,600 


550 


364 


762 


1,440 


2,960 


4,420 


8,600 


13,600 


24,000 


48,900 


600 


348 


727 


1,370 


2.810 


4,210 


8,110 


12,900 


22,900 


46,600 


650 


333 


696 


1,310 


2.690 


4,030 


7,770 


12,400 


21,900 


44,600 


700 


320 


669 


1,260 


2,590 


.3,880 


7,460 


11,900 


21,000 


42,900 


760 


308 


644 


1,210 


2,490 


3,730 


7,190 


11 ,.500 


20,300 


41,300 


800 


298 


622 


1,170 


2,410 


3,010 


6,940 


11,100 


19,600 


39,900 


850 


288 


602 


1,130 


2,330 


3,490 


6,720 


10,700 


18,900 


38,600 


900 


279 


584 


1,100 


2,260 


3.380 


6,520 


10,400 


18,400 


37,400 


950 


271 


.567 


1,070 


2.190 


3.290 


6,330 


10,100 


17,800 


30,400 


1,000 


264 


651 


1,040 


2,1.30 


.3,200 


0,150 


9,810 


17,.300 


35,400 


1,100 


250 


524 


987 


2,030 


3,030 


5,840 


9,320 


16,500 


33,600 


1,200 


239 


600 


941 


1.9.30 


2,900 


6,580 


8,890 


15.700 


32,000 


1,300 


229 


47S 


901 


1,860 


2,770 


5,340 


8,510 


16,000 


30,700 


1,400 


220 


460 


866 


1,780 


2,660 


,5,1.30 


8,180 


14,500 


29,500 


1,600 


212 


443 


834 


1,710 


2,570 


4,940 


7,880 


13,900 


28,400 


1,(J00 


206 


428 


806 


1,650 


2,480 


4,770 


7,610 


13.400 


27,400 


1,700 


198 


414 


780 


1,600 


2.400 


4.620 


7,300 


13,000 


26,500 


1,800 


192 


401 


756 


1.550 


2.330 


4.480 


7,140 


12,600 


25,700 


1,900 


186 


390 


734 


1,510 


2,260 


4,350 


6,930 


12,300 


25,000 


2,000 


181 


379 


714 


1,470 


2,200 


4,230 


6,740 


11.900 


24,300 



Note: All table entries are rounded to 3 significant digits. 



227 



Table 13-12 



2007 CALIFORNIA MECHANICAL CODE 



Table 13-12 Semi-Rigid Copper Tubing [NFPA 54: Table 6.2(f)] 



















Gas: 


Natural 




Inlet Pressure: 


Less tban 2 psi 




Pressure Drop: 


0.3 in. w.c. 




Specific Gravity: 


0.60 




Tube Size (in.) 


Nominal: 


K&L: 


'A 


% 


V4 


'A 


% 


1 


VA 


I'/S 


2 
























ACR 


'A 


■/i 


% 


'A 


% 


IVi 


IM 


— 


— 


Outside: 


0.375 


0.500 


0.625 


0.780 


0.875 


1.125 


1.375 


1.625 


2.125 


Inside:* 


0.306 


0.402 


0.527 


0.652 


0.745 


0.995 


1.245 


1.481 


1.959 


Lengtii (ft) 


Capacity in Cubic Feet of Gas per Hour 


10 


20 


42 


85 


148 


210 


448 


806 


1,270 


2,650 


20 


14 


29 


58 


102 


144 


308 


554 


873 


1,820 


30 


U 


23 


47 


82 


116 


247 


445 


701 


1,460 


40 


10 


20 


40 


70 


99 


211 


381 


600 


1.250 


50 


NA 


17 


35 


62 


88 


187 


337 


582 


1,110 


00 


NA 


16 


32 


56 


79 


170 


306 


482 


1,000 


70 


NA 


14 


29 


m 


73 


156 


281 


443 


924 


80 


NA 


13 


27 


48 


68 


145 


262 


413 


859 


90 


NA 


13 


26 


45 


64 


1,% 


245 


387 


806 


100 


NA 


12 


24 


43 


60 


129 


232 


366 


761 


125 


NA 


11 


22 


38 


f)3 


114 


206 


324 


675 


130 


NA 


10 


20 


34 


4S 


103 


186 


294 


612 


175 


NA 


NA 


IS 


31 


45 


95 


171 


270 


563 


200 


NA 


NA 


17 


29 


41 


89 


159 


251 


523 


250 


NA 


NA 


15 


20 


37 


78 


141 


223 


464 


300 


NA 


NA 


13 


23 


33 


71 


128 


202 


420 


850 


NA 


NA 


12 


22 


31 


65 


118 


186 


387 


400 


NA 


NA 


n 


20 


28 


61 


110 


173 


300 ■ 


450 


NA 


NA 


11 


19 


27 


57 


lOS 


162 


338 


500 


NA 


NA 


10 


18 


25 


54 


97 


1!J3 


319 


550 


NA 


NA 


NA 


17 


24 


51 


92 


145 


303 


600 


NA 


NA 


NA 


16 


23 


49 


88 


139 


289 


650 


NA 


NA 


NA 


15 


22 


47 


84 


133 


277 


700 


NA 


NA 


NA 


15 


21 


45 


81 


128 


266 


750 


NA 


NA 


NA 


14 


20 


•13 


78 


123 


256 


800 


NA 


NA 


NA 


14 


20 


42 


75 


119 


247 


850 


NA 


NA 


NA 


13 


19 


40 


73 


115 


239 


900 


NA 


NA ■ 


NA 


13 


18 


.39 


71 


111 


232 


950 


NA 


NA 


NA 


.18 


18 


38 


69 


108 


225 


1,000 


NA 


NA 


NA 


12 


17 


37 


67 


105 


219 


1,100 


NA 


NA 


NA 


12 


16 


35 


63 


100 


208 


1,200 


NA 


NA 


NA 


11 


10 


34 


60 


96 


199 


1,300 


NA 


NA 


NA , 


11 


15 


32 


58 


91 


190 


1,400 


NA 


NA 


NA 


10 


14 


31 


66 


88 


183 


1,500 


NA 


NA 


NA 


NA 


14 


30 


54 


84 


176 


1,600 


NA 


NA 


NA 


NA 


13 


29 


52 


82 


170 


1,700 


NA 


NA 


NA 


NA 


13 


28 


60 


79 


164 


1,800 


NA 


NA 


NA 


NA 


13 


27 


49 


77 


159 


1,900 


NA 


NA 


NA 


NA 


12 


26 


47 


74 


155 


2,000 


NA 


NA 


NA 


NA 


12 


25 


46 


72 


151 



N A means a flow of less ilian 1 cfli. 

Note: AU table entries are rounded to 3 significant digits. 

"Table capacitie.s are based on Type K copper tubing inside diameter (slio^vn) , whicli has the smallest inside 

diameter of tlie copper tubing products. 



228 



FUEL GAS PIPING 



Table 13-13 



Table 13-13 Semi-Rigid Copper Tubing [NFPA 54: table 6.2(g)] 

















Gas: 


Natural 




Inlet Pressure; 


Less than 2 psi 




Pressure Drop: 


0.5 in. w.c. 




Specific Gravity: 


0.60 




Tuh>e Size (in.) 




K&L: 


'/i 


% 


'A 


% 


■ % 


I 


I'/i 


VA 


2 


Noniinal: 
























ACR; 


■W 


'/j 


Vf. 


% 


% 


IV, 


1% 


— 


— 


Outside: 


0.S76 


0.500 


0.629 


0.750 


0.875 


1.125 


1.375 


1.625 


2.125 


Inside:* 


0.305 


0.402 


0.527 


0.652 


0.745 


0.995 


1.245 


1.481 


1.959 


Length (ft) 




' 




Capacity in 


Cubic Feet of Gas per Hour 








10 


27 


65 


111 


195 


276 


590 


l,0(i0 


1,680 


3,490 


20 


18 


3S 


77 


134 


190 


406 


7.30 


1,1 !)0 


2,400 


30 


15 


30 


61 


107 


152 


326 


6SC 


925 


1,930 


40 


13 


26 


53 


92 


131 


279 


502 


791 


1,650 


50 


11 


23 


47 


82 


116 


247 


445 


701 


1,460 


CO 


10 


21 


42 


74 


105 


224 


403 


635 


1,320 


70 


N.A 


19 


39 


(i8 


96 


206 


371 


585 


1,220 


80 


NA 


• IS 


86 


63 


90 


192 


345 


544 


1,130 


90 


NA 


17 


34 


59 


84 


ISO 


324 


610 


1,060 


100 


NA 


16 


32 


56 


79 


170 


306 


482 


1,000 


126 


NA 


14 


■28 


60 


70 


151 


271 


427 


890 


150 


NA 


13 


26 


45 


C4 


136 


246 


387 


806 


175 


NA 


12 


24 


41 


:>9 


125 


226 


.356 


742 


200 


NA 


U 


09 


39 


65 


117 


210 


331 


690 


250 


NA 


NA 


20 


34 


48 


103 


186 


294 


612 


300 


NA 


NA 


18 


31 


44 


94 


109 


266 


554 


350 


NA 


NA 


16 


28 


40 


86 


156 


245 


510 


400 


NA 


NA 


15 


26 


38 


80 


144 


228 


474 


450 


NA 


NA 


14 


25 


35 


75 


135 


214 


445 


500 


MA 


NA 


13 


23 


33 


71 


128 


202 


420 


550 


NA 


NA 


13 


22 


32 


68 


122 


192 


399 


COO 


NA 


NA 


12 


21 


80 


64 


no 


183 


381 


050 


NA 


NA 


12 


20 


29 


02 


111 


175 


365 


700 


NA 


NA 


11 


20 


28 


59 


107 


168 


360 


750 


NA 


NA 


11 


19 


27 


67 


103 


162 


338 


SOO 


NA 


NA 


30 


18 


26 


55 


99 


156 


326 


8S0 


NA 


NA 


10 


18 


25 


63 


96 


151 


316 


900 


NA 


NA 


NA 


17 


24 


52 


93 


147 


306 


950 


NA 


NA 


NA 


17 


24 


60 


90 


143 


297 


1.000 


NA 


NA 


NA 


16 


23 


49 


88 


139 


289 


1,100 


NA 


NA 


NA 


15 


22 


46 


84 


132 


274 


1,200 


NA 


NA 


NA 


15 


21 


44 


80 


126 


262 


1,300 


NA 


NA 


NA 


14 


20 


42 


76 


120 


261 


1,-1.00 


NA 


NA 


NA 


13 


19 


41 


73 


116 


241 


1,.500 


NA 


NA 


NA 


13 


18 


39 


71 


111 


232 


1,600 


NA 


NA 


NA 


IS 


IS 


38 


68 


108 


224 


1,700 


NA 


NA 


NA 


12 


17 


37 


65 


104 


217 


1,800 


NA 


NA 


NA 


12 


17 


36 


()4 


101 


210 


1,900 


NA 


NA 


NA 


11 


16 


35 


62 


98 


204 


2,000 


NA 


NA 


NA 


11 


16 


34 


60 


95 


199 



NAraeans a flow of less than 10 clli. 

Note; All table entries are rounded to 3 .significant digits. 

'Table capacities are based on Type K copper tubing inside diameter (shown) , which has the smallest inside 

diameter of the copper tubing products. 



229 



Table 13-14 



2007 CALIFORNIA MECHANICAL CODE 



Table 13-14 Semi-Rigid Copper Tubing [NFPA 54: Table 6.2(h)] 





Gas: 


Natural 




Inlet Pressure: 


Less than 2 psj 




Pressure Drop: 


1.0 in. w.c. 




Specific Gmvity: 


0.60 


SPECIAL USE: Tiibe Sizing Between House Line Regulator and the AppUance. 



Tube Size (in.) 



Nominal: 


K&L: 


Vt 


% 


'/j 


Va 


% 


I 


VA 


VA 


2 
























ACR: 


'A 


W 


% 


'A 


% 


VA, 


1% 


— 


— 


Outside: 


0.375 


0.500 


0.625 


0.750 


0.875 


1.125 


1. 375 


1.625 


2.125 


Inside;* 


0.306 


0.402 


0.527 


0.662 


0.745 


0.996 


1.245 


1.481 


1.959 


Lengtli (ft) 








Capacity in 


Oubic Feet of G.ts per Hour 








10 


39 


80 


162 


283 


402 


859 


1,.550 


2,440 


6,080 


20 


27 


55 


111 


196 


276 


690 


1,060 


1,6S0 


3,490 


30 


21 


44 


89 


156 


222 


474 


853 


1,360 


2,800 


40 


18 


38 


77 


134 


190 


406 


730 


1,160 


2,400 


50 


16 


.33 


68 


119 


168 


369 


647 


1,020 


2,130 


60 


15 


30 


61 


107 


152 


326 


686 


925 


1,930 


70 


13 


28 


67 


99 


140 


300 


539 


851 


1,770 


80 


13 


26 


.93 


92 


131 


279 


502 


791 


1,660 


90 


12 


24 


49 


86 


122 


262 


471 


742 


1,650 


100 


11 


28 


47 


82 


116 


247 


446 


701 


1,460 


125 


NA 


20 


41 


72 


103 


219 


394 


622 


1,290 


160 


NA 


18 


37 


66 


93 


198 


357 


663 


1,170 


175 


NA 


17 


34 


60 


85 


183 


329 


618 


1,080 


200 


NA 


IC 


32 


56 


79 


170 


306 


482 


1,000 


260 


NA 


14 


28 


60 


70 


161 


271 


427 


890 


300 


NA 


13 


26 


45 


64 


136 


245 


387 


806 


350 


NA 


12 


24 


41 


69 


125 


226 


356 


742 


■100 


NA 


11 


22 


39 


65 


117 


210 


331 


690 


450 


NA 


10 


21 


36 


61 


110 


197 


311 


647 


500 


NA 


NA 


20 


34 


48 


103 


186 


294 


612 


550 


NA 


NA 


19 


32 


46 


98 


177 


279 


581 


600 


NA 


NA 


IS 


31 


44 


94 


169 


266 


554 


650 


NA 


NA 


17 


30 


42 


90 


162 


265 


531 


700 


NA 


NA 


16 


28 


40 


86 


156 


245 


510 


760 


NA 


NA 


16 


27 


39 


83 


1.50 


236 


491 


800 


NA 


NA 


16 


26 


38 


80 


144 


228 


474 


850 


NA 


NA 


16 


26 


36 


78 


140 


220 


459 


800 


NA 


NA 


14 


25 


36 


75 


136 


214 


445 


950 


NA 


NA 


14 


24 


34 


73 


132 


207 


432 


1,000 


NA 


NA 


13 


23 


33 


71 


128 


202 


420 


1,100 


NA 


NA 


13 


22 


32 


68 


122 


192 


399 


1,200 


NA 


NA 


12 


21 


30 


64 


116 


183 


381 


1,300 


NA 


NA 


12 


20 


29 


62 


111 


175 


365 


1,400 


NA 


NA 


11 


20 


28 


.69 


107 


168 


350 


1,500 


NA 


NA 


11 


10 


27 


57 


103 


162 


338 


1,600 


NA 


NA 


10 


18 


26 


66 


99 


166 


326 


1,700 


NA 


NA 


10 


18 


25 


53 


96 


151 


315 


1,800 


NA 


NA 


NA 


17 


24 


62 


93 


147 


306 


1,900 


NA 


NA 


NA 


17 


24 


50 


90 


143 


297 


2,000 


NA 


NA 


NA 


16 


23 


49 


88 


1.39 


289 



NA means a flow of less than 10 cfli. 

Note: All table entries are rounded to 3 significant digits. 

"Table capacities are based on Type K copper tiilMng inside diameter (.shown ) , which has the .smallest inside 

diameter of the copper tubing products. 



230 



FUEL GAS PIPING 



Table 13-15 



Table 13-15 Semi-Rigid Copper Tubing [NFPA 54: Table 6.2(i)] 

















Gas: 


Natural 




Inlet Pressure: 


Less tlion 2.0 


psi 




Pressure Drop: 


17.0 in. w.c. 




Specific Gravity: 


0.60 




Tube Size (in.) 




K&L: 


Vi 


% 


Vi 


y« 


»/i 


1 


I'/i 


VA 


2 


Nominal*. 
























ACR: 


'A 


V4 


% 


% 


% 


IV* 


iy« 


— 


— 


Oulsidc! 


0.375 


0.500 


0.625 


0.750 


0.876 


1.125 


1.375 


1.G2S 


2.125 


Inside:* 


0.305 


0.402 


0.527 


0.652 


0.745 


0.995 


1.245 


1.481 


1.959 


Length (ft) 


Capacity in Cubic Feet of Gas per Hour 


.10 


ISO 


391 


796 


1,390 


1,970 


4,220 


7,!J90 


12,000 


24,900 


20 


130 


209 


547 


95(i 


1,360 


2,900 


5,220 


8,230 


17,100 


30 


106 


216 


•139 


768 


1,090 


2,330 


4,190 


6,610 


1.3,800 


-10 


90 


185 


376 


0B7 


932 


1.990 


.3,r)90 


3,650 


11,800 


50 


79 


164 


333 


582 


820 


1,770 


3,180 


■),010 


10,400 


GO 


72 


148 


302 


528 


749 


1,600 


2,880 


4.540 


9,460 


70 


66 


137 


278 


486 


689 


1,4.70 


2,650 


. 4,180 


8,700 


80 


' 62 


'l27 


258 


452 


641 


1,370 


2,460 


8,890 


8,090 


90 


38 


119 


243 


424 


601 


1,280 


2,310 


3,()50 


7,i590 


J 00 


56 


113 


229 


400 


568 


1,210 


2,180 


3,440 


7.170 


125 


4« 


100 


203 


365 


603 


1,080 


1,940 


3,030 


6,360 


150 


44 


. 90 


184 


321 


456 


974 


1,750 


2,770 


6,760 


:17S 


40 


83 


169 


290 


420 


896 


1,610 


2,640 


5,300 


200 


38 


' . 77 


157 


275 


890 


834 


1,500 


2,370 


4,930 . 


2S0 


33 


69 


140 


244 


346 


739 


1,830 


2,100 


4,370 


300 


30 


02 


126 


221 


313 


670 


1,210 


1,900 


3,900 


350 


28 


57 


116 


203 


288 


616 


1,110 


1,760 


3,640 


400 


26 


53 


108 


189 


268 


573 


1,030 


1,630 


3,390 


450 


24 


50 


102 


177 


262 


538 


968 


1,530 


3,180 


500 


23 


47 


96 


KiS 


23S 


508 


914 


1,440 


3,000 


550 


22 


45 


91 


lfi9 


226 


482 


808 


1,370 


2,860 


000 


21 


43 


. 87 


162 


215 


460 


829 


1,310 


2,720 


650 


20 


41 


S3 


143 


206 


441 


793 


1,260 


2.610 


700 


19 


39 


80 


140 


198 


423 


762 


1,200 


2,500 


760 


18 


38 


77 


135 


191 


408 


734 


1,160 


2,410 


800 


18 


37 


74 


130 


184 


394 


709 


1,120 


2,330 


850 


17 


.35 


72 


126 


178 


.381 


(>86 


1,080 


2,260 


000 


17 


34 


70 


122 


173 


370 


666 


1,060 


2,180 


950 


16 


33 


68 


lis 


168 


369 


646 


1,020 


2,120 


1,000 


10 


32 


66 


115 


163 


349 


628 


991 


2,060 


1,100 


15 


31 


63 


109 


1.55 


332 


697 


941 


1,960 


1,200 


14 


29 


60 


1.04 


148 


316 


569 


898 


1,870 


1,300 


14 


28 


57 


100 


142 


303 


.545 


860 


1,790 


1,400 


13 


27 


65 


90 


1.16 


291 


524 


826 


1,720 


],.500 


13 


26 


58 


93 


131 


280 


603 


796 


1,660 


1,600 


12 


26 


51 


89 


127 


271 


487 


768 


1,600 


1,700 


12 


24 


49 


86 


123 


262 


472 


744 


1,560 


1,800 


11 


24 


48 


84 


119 


234 


457 


721 


1,500 


1,900 


11 


23 


47 


81 


115 


247 


4.44 


700 


1,460 


2,000 


11 


22 


45 


79 


112 


240 


432 


681 


1,420 



Note: All table entries are rounded to .S .significant digits. 

"Table capacities are based on T)pe K copper tubing inside diameter (shown), wliicli has ri>e smallest inside 

diameter of.' the copper tubing products. 



231 



Table 13-16 



2007 CALIFORNIA MECHANICAL CODE 



Table 13-16 Semi-Rigid Copper Tubing [NFPA 54: Table 6.2(j)] 

















Gas: 


Natural 




Inlet Pressure: 


2.0 psi 




Pressure Drop: 


1.0 psi 




Specific Gravity: 


0.60 




Tube Size (in.) 


Nominal: 


K&L: 


Vt 


Vb 


V4 


Vs 


% 


1 


VA 


1V4 


2 
























ACR: 


Vb 


'A 


"i* 


Vi 


% 


VA 


1% 


— 


— 


Outside: 


0.375 


0.500 


0.625 


0.750 


0.875 


1.125 


1.375 


1.625 


2.125 


Inside:' 


0.305 


0.402 


0.527 


0.652 


0.745 


0.995 


1.245 


1.481 


1.959 


Length (ft) 








Capacity in 


Cubic Feet of Gas per Hour 








10 


245 


506 


1,030 


1,800 


2,550 


5,450 


9,820 


15,500 


32,200 


20 


169 


348 


708 


1,240 


1,760 


3,750 


6,750 


10,600 


22,200 


30 


13r> 


279 


568 


993 


1,410 


.3,010 


5,420 


8,550 


17,800 


40 


U(i 


239 


486 


850 


1,210 


2.580 


4,640 


7.310 


15,200 


50 


103 


212 


431 


764 


1,070 


2,280 


4,110 


6,480 


13,500 


60 


93 


192 


391 


683 


969 


2,070 


3,730 


5,870 


12,200 


70 


86 


177 


359 


628 


891 


1.900 


3,430 


5,400 


11,300 


80 


80 


164 


334 


584 


829 


1.770 


3,190 


5,030 


10,600 


90 


75 


154 


314 


548 


778 


1,660 


2,990 


4,720 


9,820 


100 


71 


146 


296 


518 


735 


1,670 


2,830 


4.430 


9,280 


125 


63 


129 


263 


459 


651 


1,390 


2,500 


3,950 


8,220 


IBO 


57 


117 


238 


416 


.590 


1,260 


2,270 


3,580 


7,460 


175 


52 


108 


219 


383 


643 


1,160 


2,090 


3,290 


6,850 


200 


49 


100 


204 


356 


506 


1,080 


1,940 


3,060 


6,380 


250 


43 


89 


181 


315 


448 


956 


1,720 


2,710 


5,650 


300 


,39 


80 


164 


286 


406 


866 


1,660 


2,460 


6.120 


350 


36 


74 


150 


263 


373 


797 


1,430 


2,260 


4.710 


400 


33 


69 


140 


245 


347 


741 


1,330 


2,100 


4,380 


450 


31 


65 


131 


230 


326 


696 


1,250 


1,970 


4,U0 


500 


30 


61 


124 


217 


308 


657 


1,180 


1,870 


3,880 


550 


28 


68 


118 


206 


292 


624 


1,120 


1,770 


3.690 


SOO 


27 


55 


112 


196 


279 


595 


1,070 


1,690 


3.520 


1)50 


26 


53 


108 


188 


267 


570 


1,030 


1,620 


3.370 


700 


26 


51 


103 


181 


266 


.548 


986 


1,550 


3,240 


750 


24 


48 


100 


174 


247 


528 


950 


1,600 


3,120 


800 


23 


47 


96 


168 


239 


610 


917 


1,450 


,3,010 


850 


22 


46 


93 


163 


231 


493 


888 


1,400 


2,920 


900 


22 


44 


90 


158 


224 


478 


861 


1,360 


2,8,30 


950 


21 


43 


88 


153 


217 


464 


836 


1,320 


2,740 


1,000 


20 


42 


83 


149 


211 


452 


813 


1,280 


2,670 


1,100 


19 


40 


81 


142 


201 


429 


772 


1,220 


2,540 


1,200 


IS 


38 


77 


135 


192 


409 


737 


1,160 


2,420 


1,300 


18 


36 


74 


129 


183 


392 


705 


1,110 


2,320 


1,400 


17 


35 


71 


124 


176 


376 


678 


1,070 


2,230 


1.500 


16 


34 


68 


120 


170 


363 


653 


1,030 


2,140 


1,000 


16 


33 


66 


116 


164 


350 


530 


994 


2,070 


1,700 


15 


31 


64 


112 


169 


339 


610 


962 


2,000 


1,800 


15 


30 


62 


108 


164 


329 


592 


933 


1,940 


1,900 


14 


30 


60 


105 


149 


319 


675 


906 


1,890 


2,000 


14 


29 


60 


102 


145 


310 


,559 


881 


1,830 



Note: All table entries are rounded to 3 significant digits. 

"Table capacities are based on Type K copper tubing inside diameter (shown) , wliich has the smallest inside 

diameter of the copper tubing producLS. 



232 



FUEL GAS PIPING 



Table 13-17 



Table 13-17 Semi-Rigid Copper Tubing [NFPA 54: Table 6.2(k)] 



Gas: Natural 



Inlet Pressure: 



Pressure Drop: 



Specific Gravity: 



2.0 psi 



1.5 psi 





■ SPECIAL USE: Pipe Sizing Between Poiiil ofDcIivciT and Uic House Line Regulator. Total Load Supplied by a 
' ' . .'■ Single House Line RegiiLitoi- Not Exceeding 150 Cubic Feet per I-Iour.+ 






Tube Size (in.) 




K&L: 


'A 


y» 


'A 


•A 


s/i 


1 


1'/. 


Wi 


2 




ACR: 


% 


<A 


% 


'A 


'/« 


W» 


V/a 


— 


— 


Outside: 


0.375 


0.500 


0.626 


0.750 


0.875 


1.125 


1.375 


1.626 


2.125 


Inside:* 


0.305 


0.402 


0.527 


0.652 


0.746 


0.995 


1.246 


1.481 


1.959 


Lengtli (tl) 


Capacity in Cubic Feet of Gas per Hour 


10 
20 
30 
40 
.00 


303 
208 
167 
143 

127 


025 
430 
345 
295 
262 


1,270 
874 
702 
001 
632 


2,220 
1,630 
1,230 
1,060 
931 


3,160 
2,170 
1,74.0 
1,490 
1,320 


0,740 
4,630 
3,720 
3,180 
2,820 


12,100 
8,330 
0,090 
6,730 
5,080 


. 19,100 
13,100 
10,600 
9,030 
8,000 


39,800 
27,400 
22,000 
18,800 
16,700 


GO 
70 
80 
90 
100 


115 
106 
98 
92 
87 


237 
218 
203 
190 
. 180 


482 
444 
413 
387 
366 


843 
776 
722 
677 
640 


1,200 

1.100 

1,020 

961 

907 


2,560 
2,350 
2,190 
2,050 
1,940 


4,600 
4,230 
3,940 
3,690 
3,490 


7,250 
6,670 
6,210 
6,820 
6,600 


15,100 
13,900 
12,900 
12,100 
11,500 


126 
1!50 
175 
200 
250 


77 
70 
1)4 
00 
53 


159 
144 
133 
124 
■ 110 


824 
294 
270 
252 
228 


61)7 
514 
472 
440 
390 


804 
729 
670 
624 
553 


1,720 
1,560 
1,430 
1,330 
1,180 


3,090 
2,800 
2,680 
2,400 
2,1.30 


4,880 
4,42(1 
4,060 
.3,780 
3,350 


10,200 
9,200 
8,460 
7,870 
0,980 


300 
850 
. 400 
450 
500 


48 
44 
41 
39 
30 


99 
91 
85 
80 
75 


202 
186 
173 
102 
1.63 


363 
326 
302 
283 
268 


.601 
461 
429 
4.02 
380 


1,070 
984 
916 
8.59 
811 


1,930 
1,770 
1,660 
1,550 
1,460 


3,040 
2,790 
2,600 
2,440 
2,300 


6,320 
5,820 
:),410 
!),080 
4,800 


560 
600 
050 
700 
750 


35 
38 
32 
80 
29 


72 
08 
65 
63 
60 


146 
139 
,133 
128 
123 


254 
243 
232 
223 
215 


361 
344 
330 
317 
305 


771 
735 
704 
676 
632 


1,390 
1,320 
1,270 
1,220 
1,170 


2,190 
2,090 
2.000 
1,920 
1,860 


4,560 
4.350 
4,160 
4,000 
. 3,850 


SCO 
850 
900 
950 
1,000 


28 
27 
27 
26 

25 


58 
67 
55 
63 
52 


119 
115 
111 
108 
105 


208 
201 
195 
189 
184 


295 
285 
270 
268 
261 


629 
009 
590 
573 
558 


1,130 
1,100 
1.000 
1,030 
1,000 


1,790 
1,730 
1,680 
1,630 
1,58(1 


3,720 
3,600 
3,490 
3,390 
3,300 


1,100 
1,200 
1,300 
1,400 
1,500 


24 
23 
22 
21 
20 


49 
47 
45 
43 
42 


100 
96 
91 . 
88 
S5 


176 
11)7 
100 
153 
148 


248 
237 
227 
218 
210 


530 
505 
484 
465 
448 


964 
910 
871 
S37 
806 


1,500 
1,430 
1,370 
1,820 
1,270 


3,130 
2,990 
2,860 
2,750 
2,660 


1,000 
1,700 
1,800 
1,900 
2,000 


19 
19 
18 

la 

17 


. 40 
39 
38 
37 
36 


82 
79 
77 
74 
72 


143 
138 
134 
130 
126 


202 
196 
190 
184 
179 


432 
419 
406 
394 
888 


779 
763 
731 
709 
090 


1,230 
1,190 
1,150 
1,120 
1,090 


2,560 
2,470 
2,400 
2,330 
2,270 



Note: All table enttics are rounded to 3 .significant, digits. 

"Table capacities are ba.sed on T)i)e K copper tubing inside diameter (.shown) , which has die smallest inside 

diameter of die copper ttibing products. 

*When this table is xised to size the tubing upstream of a line pressure regulator, tlie pipe or tubing down- 

.strcam of die line pre.s.sure regulator .shall be sized using a pressure drop no greater than 1 in. w.c. 



233 



Table 13-18 



2007 CALIFORNIA MECHANICAL CODE 



Table 13-18 Semi-Rigid Copper Tubing [NFPA 54: Table 6.2(1)] 

















Gas: 


Natural 




Inlet Pressure: 


5.0 psi 




Pressure Drop: 


3.5 psi 




Specific Gravity: 


0.60 




Tube Size (in.) 




K&L: 


Vt 


% 


Vt 


% 


3/1 


1 


in 


IVi 


2 


























ACR: 


H 


'A 


V« 


% 


'/» 


l'/8 


IW 


— 


— 


Outside: 


0.375 


0.500 


0.625 


0.750 


0.875 


1.125 


1.375 


1.625 


2.125 


Inside:' 


0.305 


0.402 


0.527 


0.652 


0.745 


0.995 


1.245 


1.481 


1.959 


Lengfli (ft) 


Capacity in Cubic Feet of Gas per Hour 


10 


511 


1,050 


2,140 


3,750 


5,320 


11,400 


20,400 


32,200 


67,100 


20 


.351 


724 


1,470 


2,680 


.3,650 


7,800 


14,000 


22,200 


46,100 


30 


282 


582 


1,180 


2,070 


2,930 


6,270 


11,300 


17,800 


37,000 


•10 


241 


498 


1,010 


1,770 


2,510 


5,360 


9,060 


15,200 


31,700 


SO 


214 


441 


898 


1„570 


2,230 


4,760 


8,560 


13,500 


28,100 


60 


194 


400 


813 


1,420 


2,020 


4,310 


7,760 


12,200 


25,500 


70 


178 


3B8 


748 


1,310 


1,860 


3,960 


7,130 


11,200 


23,400 


80 


106 


342 


696 


1,220 


1,730 


3,690 


6,640 


10,500 


21,800 


90 


156 


321 


6!)3 


1.140 


1,620 


3,460 


6,230 


9,820 


20,400 


100 


147 


303 


617 


1,080 


1,630 


3,270 


5,880 


9,270 


19,300 


123 


130 


269 


647 


955 


1,360 


2,900 


5,210 


8,220 


17,100 


150 


118 


243 


495 


866 


1,230 


2,620 


4,720 


7,450 


15,500 


175 


109 


224 


456 


798 


1,130 


2,410 


4,350 


6,850 


14,300 


200 


101 


208 


424 


741 


1,050 


2,250 


4,040 


6,370 


13,300 


250 


90 


185 


376 


657 


932 


1,990 


3,580 


5,660 


11,800 


300 


81 


167 


340 


,595 


844 


1,800 


3,260 


5,120 


10,700 


350 


75 


164 


313 


547 


777 


1,660 


2,990 


4,710 


9,810 


400 


00 


143 


291 


509 


722 


1,540 


2,780 


4,380 


9,120 


d50 


65 


134 


273 


478 


678 


1,450 


2,610 


4,110 


8,660 


500 


02 


127 


2S8 


451 


640 


1,370 


2,400 


3,880 


8,090 


550 


58 


121 


245 


42!) 


608 


1,300 


2,340 


3,690 


7,680 


COO 


50 


116 


234 


40a 


580 


1,240 


2,230 


3,620 


7,330 


1)50 


53 


no 


224 


392 


556 


1,190 


2,140 


3,370 


7,020 


700 


51 


106 


215 


376 


.5,34 


1,140 


2,060 


3,240 


6,740 


750 


49 


102 


207 


362 


51'1 


1,100 


1,980 


3,120 


6,490 


800 


48 


98 


200 


350 


497 


1,060 


1,910 


3,010 


6,270 


860 


46 


95 


194 


339 


481 


1,030 


1,850 


2,910 


6,070 


900 


46 


92 


188 


328 


466 


1,000 


1,790 


2,820 


,5,880 


950 


43 


90 


182 


319 


452 


967 


1,740 


2,740 


,5,710 


1,000 


42 


87 


177 


310 


440 


940 


1,690 


2,670 


5,560 


1,100 


40 


S3 


169 


295 


418 


893 


1,610 


2,530 


5,280 


1,200 


38 


79 


101 


281 


399 


852 


1,530 


2,420 


5,040 


1,300 


37 


76 


164 


269 


382 


816 


1,470 


2,320 


4,820 


1,400 


36 


73 


148 


259 


367 


784 


1,410 


2,220 


4,630 


1,500 


34 


70 


143 


249 


353 


756 


1,.360 


2,140 


4,460 


1,000 


.33 


68 


138 


241 


341 


729 


1,.3]0 


2,070 


4,310 


1,700 


32 


65 


133 


233 


330 


705 


1,270 


2,000 


4,170 


1,800 


31 


63 


129 


220 


320 


084 


1,230 


1,940 


4,040 


1,900 


30 


62 


125 


219 


311 


664 


1,200 


1,890 


3,930 


2,000 


29 


60 


122 


213 


302 


646 


1,160 


1,830 


3,820 



Note: AJl table entries are rounded to 3 significant digits. 

^Table capacities aie based on Type K copper tubing inside diameter (shown) , which has tlie smallest inside 

diameter of the copper tubing products. 



234 



FUEL GAS PIPING 



Table 13-19 



Table 13-19 Corrugated Stainless Steel Tubing (CSST) [NFPA 54: Table 6.2(m)] 























Gas: 


Natural 






Inlet Pressure: 


Less tlian 2 psi 




Pressure Drop: 


0.5 in. w. 


c. 




Specific Gravity: 


0.60 




Tul)eSize(EHD)* 


Flow Designation: 


13 


15 


IS 


19 


23 


25 


30 


31 


37 


46 


48 


GO 


62 


Lengtii (ft) 


Capacity in Cubic Feet of Gas per Hour 


5 


■10 


03 


115 


134 


225 


270 


471 


540 


895 


1,790 


2,070 


3,660 


4,140 


10 


32 


ii 


82 


95 


101 


192 


330 


383 


639 


1,200 


1,470 


2,600 


2,930 


16 


25 


35 


00 


77 


IS2 


157 


207 


310 


524 


1,030 


1,200 


2,140 


2,400 


20 


22 


31 


58 


67 


116 


137 


231 


269 


450 


888 


1,050 


1,850 


2,080 


25 


19 


27 


52 


00 


104 


122 


200 


240 


409 


793 


936 


1,000 


1,860 


30 


18 


25 


47 


55 


96 


112 


188 


218 


374 


723 


850 


1,520 


1,700 


40 


15 


21 


41 


47 


83 


97 


102 


188 


325 


62S 


742 


1„320 


1,470 


50 


13 


19 


37 


42 


75 


87 


144 


168 


292 


559 


005 


1,180 


1,320 


00 


12 


17 


34 


38 


08 


80 


131 


153 


207 


509 


608 


1,080 


1,200 


70 


11 


IS 


31 


36 


63 


74 


121 


141 


248 


471 


503 


1,000 


1,110 


80 


10 


15 


29 


33 


60 


69 


113 


132 


232 


440 


527 


940 


1,040 


80 


10 


14 


28 


32 


57 


05 


107 


125 


219 


415 


498 


887 


983 


100 


9 


13 


20 


30 


54 


62 


101 


118 


208 


393 


472 


843 


933 


IBO 


7 


10 


20 


23 


42 


48 


78 


91 


171 


320 


387 


091 


762 


200 





9 


18 


21 


38 


44 


71 


82 


148 


277 


330 


600 


661 


250 


5 


8 


16 


19 


34 


39 


63 


74 


133 


247 


301 


538 


591 


300 


5 


7 


15 


17 


32 


36 


67 


67 


95 


220 


275 


492 


540 



*EHD = Equivalent Hydraulic Diameter, wliicli is a measure of tile relative liydraulic elllciency between 

different tubing sizes. Tlie greater the value of EHD, tlie greater the gas capacity of tlie ttibing. 

Notes; 

(1) Table includes losses for four 90 degree bends and ttvo end fittings. Tubing runs with larger nuinbei-s of 
bends aud/or fittings shall be increased by an equivalent length of ttiljing to the following equadon:£=1.3»7, 
where L is addidonal lengdi (ft) of ttibing and n is die number of additional fittings and/or bends. 

(2) All table entries are rounded to ?> .significant digit-S. 



235 



Table 13-20 



2007 CALIFORNIA MECHANICAL CODE 



Table 13-20 Corrugated Stainless Steel Tubing (CSST) [NFPA 54: Table 6.2(n)] 























Gas: 


Natural 






Inlet Pressure: 


Less than S 


psi 




Pressure Drop; 


3.0 in. w.c. 




Specific Gravity: 


0.60 




Tube Size (EHD)» 


Flow Designation: 


13 


15 


18 


19 


23 


25 


30 


31 


37 


46 


48 


GO 


62 


Length (ft) 


Capacity in Cubic Feet of Gas per Hour 


5 


120 


100 


277 


327 


529 


649 


1,180 


1,370 


2,140 


4,430 


5,010 


8,800 


10.100 


10 


83 


112 


197 


231 


380 


462 


828 


958 


1,630 


3,200 


3.560 


6,270 


7,160 


IS 


67 


90 


161 


189 


313 


379 


673 


778 


1,250 


2,540 


2,910 


5,140 


5,850 


20 


57 


78 


140 


164 


273 


329 


680 


672 


1,090 


2,200 


2,630 


4,460 


5,070 


2B 


51 


69 


125 


147 


246 


295 


518 


599 


978 


1,960 


2,270 


4,000 


4,540 


30 


46 


63 


115 


134 


226 


270 


471 


546 


896 


1,790 


2,070 


3.660 


4,140 


40 


39 


54 


100 


116 


196 . 


234 


407 


471 


778 


1,SS0 


1,800 


3,180 


3,590 


50 


35 


48 


89 


104 


176 


210 


363 


421 


698 


1,380 


1,610 


2,850 


3,210 


60 


32 


44 


82 


95 


161 


192 


330 


383 


639 


1,260 


1,470 


2,600 


2,930 


70 


29 


41 


70 


88 


150 


178 


306 


355 


593 


1,170 


1,360 


2,420 


2.720 


80 


27 


38 


71 


82 


141 


167 


285 


.331 


555 


1,090 


1,280 


2,260 


2.540 


90 


26 


36 


1)7 


77 


133 


157 


21)8 


311 


524 


1,030 


1,20(1 


2,140 


2,400 


100 


24 


34 


63 


73 


126 


149 


254 


295 


498 


974 


1,140 


2,030 


2,280 


150 


19 


27 


52 


60 


104 


122 


206 


240 


409 


793 


936 


1,660 


1,860 


200 


17 


23 


45 


52 


91 


106 


178 


207 


365 


fi8B 


812 


1,440 


1,610 


2S0 


15 


21 


40 


46 


82 


95 


159 


184 


819 


613 


728 


1,290 


1,440 


300 


13 


19 


37 


42 


75 


87 


144 


168 


234 


559 


665 


1.180 


1,320 



*EHD = Equivalent Hydraulic Diameter, which is a measure of the relative hydraulic efficiency between 

different tubing sizes. The greater tlie value of EHD, the greater the gas capacity of the tubing. 

Notes: 

(1) Table includes losses for four 90 degree bends and two end fittings. Tubing runs witli larger numbers of 
bends and/or fittings shall be increased by an eqttivalent length of tubing to the following equation: /_ = l.Sn, 
where L is additional length (ft) of tubing and n is tlie number of additional fittings and/or bends. 

(2) All table entries are rounded to S significant digits. 



236 



FUEL GAS PIPING 



Table 13-21 



Table 13-21 Corrugated Stainless Steel Tubing (CSST) [NFPA 54: Table 6.2(o)] 























Gas: 


Natural 






Inlet Pressure: 


Less than 2 psi 




Pressure Drop: 


6.0 in. Tv.c. 




Specific Gravity: 


0.60 




Tube Size (EHD)* 


Kow Designation: 


13 


15 


18 


19 


23 


25 


30 


31 


37 


46 


48 


60 


62 


Length (ft) 


Capacity in Ciiljic Feet of Gas per Hour 


B 


173 


229 


389 


461 


737 


911 


1,690 


1,950 


3,000 


0,280 


7,050 


12,400 


14,260 


10 


120 


160 


277 


327 


529 


649 


1,180 


1,370 


2,140 


4,430 


6,010 


8,800 


10,100 


15 


96 


130 


227 


207 


486 


532 


960 


1,110 


1,700 


3,610 


4,100 


7,210 


8,200 


20 


83 


112 


197 


281 


380 


4B2 


828 


958 


1,530 


3,120 


3,5fi0 


6,270 


7,160 


25 


74 


99 


176 


207 


342 


414 


739 


866 


1,370 


2,790 


3,190 


.5,620 


6,400 


30 


67 


90 


161 


189 


313 


379 


673 


77S 


1,250 


2,540 


2,910 


5,140 


5,850 


40 


57 


78 


140 


164 


27S 


329 


680 


672 


1,090 


2,200 


2,530 


4,460 


5,070 


50 


51 


69 


125 


147 


245 


295 


518 


699 


978 


1,960 


2,270 


4,000 


4,540 


00 


46 


63 


115 


134 


225 


270 


471 


546 


895 


1,790 


2,070 


3,600 


4,140 


70 


42 


58 


108 


124 


209 


250 


435 


505 


830 


1,660 


1,920 


3,390 


3,840 


80 


39 


. 54 


100 


116 


196 


234 . 


407 


471 


778 


1,650 


1,800 


.3,180 


3,690 


90 


87 


SI 


94 


109. 


185 


221 


383 


444 


736 


1,460 


1,700 


3,000 


3,390 


100 


35 


48 


89 


104 


176 . 


210 


363 


421 


098 


1,380 


1,010 


2,850 


3,210 


150 


28 


39 


73 


85 


145 


172 


294 


342 


573 


1,130 


1,320 


2,340 


2,630 


200 


24 


34 


63 


73 


126 


149 


254 


295 


498 


074 


1,140 


2,030 


2,280 


250 


21 


30 


57 


66 


114 


134 


22fi 


263 


447 


870 


1,020 


1,820 


2,040 


300 


19 


27 


52 


60 


104 


122 


206 


240 


409 


793 


fl3(i 


1,660 


1,800 



*EHD = Equivalent Hydraulic Diameter, whidi is a measure of the relative hydraulic efticienc)' Ijetween 

differeut tubing shea. The greater die value of EHD, the greater the gas capacity of the tubing. 

Notes: 

(1) Table includes losses for four 90-degree bends and two end fittings. Tubing runs witli larger numbers of 
iDends and/or (itdngs shall be increased by an equiralent length of tubing to the following equation: L=1.3n, 
where L is additional lengdi (ft) of tubing and n is the miinber of additJotuil fittings and/or bends. 

(2) All table entries are rounded to S significant digits. 



237 



Table 13-22 



2007 CALIFORNIA MECHANICAL CODE 



Table 13-22 Corrugated Stainless Steel Tubing (CSST) [NFPA 54: Table 6.2(p)] 























Gas: 


Natural 






Inlet Pressure: 


2.0 psi 




Pressure Drop: 


1.0 psi 




Specific Gravity: 


0.60 




Tube Size (EHD)» 


Plow Designation: 


13 


15 


18 


19 


23 


25 


30 


31 


37 


46 


48 


60 


62 


Length (ft) 


Capacity in Cubic Feet of Gas per Hour 


10 


270 


363 


587 


700 


1,100 


1,370 


2,690 


2,990 


4,510 


9,600 


10,700 


18,600 


21,600 


25 


161) 


220 


374 


444 


709 


876 


1,620 


1,870 


2,890 


6,040 


6,780 


11,900 


13,700 


30 


151 


200 


342 


405 


660 


801 


1,480 


1,700 


2,640 


5,510 


6,200 


10,900 


12,500 


40 


129 


172 


297 


351 


567 


096 


1,270 


1,470 


2,300 


4,760 


5,380 


9,440 


10,900 


60 


116 


164 


266 


314 


610 


624 


1,140 


1,310 


2,060 


4,260 


4,820 


8,470 


9,720 


78 


93 


124 


218 


257 


420 


512 


922 


1,070 


1,690 


3,470 


3,950 


6,940 


7,940 


80 


89 


120 


211 


249 


407 


496 


892 


1,0.30 


1,640 


3,360 


3,820 


6,730 


7,690 


100 


79 


107 


189 


222 


366 


445 


795 


920 


1,470 


3,000 


3,420 


6,030 


6,880 


150 


64 


87 


155 


182 


302 


364 


646 


748 


1,210 


2,440 


2,800 


4,940 


5,620 


200 


55 


75 


135 


157 


263 


317 


557 


643 


1,050 


2,110 


2,430 


4,290 


4,870 


250 


49 


67 


121 


141 


236 


284 


497 


570 


941 


1,890 


2,180 


3,850 


4,360 


300 


44 


61 


110 


129 


217 


260 


453 


525 


862 


1,720 


1,990 


3,520 


3,980 


400 


S8 


62 


96 


111 


189 


225 


390 


453 


749 


1,490 


1,730 


3,060 


3,450 


500 


34 


4S 


86 


100 


170 


202 


348 


404 


662 


1„330 


1,560 


2,740 


3,090 



*EHD = Equivalent Hydraulic Diameter, which is a measure of the relative liydraxilic efficiency between 

different tubing sizes. Tlie greater the value of EHD, the greater tiie gas capacity of the tubing. 

Notes: 

(1) Table does not include effect of pressure drop acro.ss the line regulator. Wiere regulator loss exceeds 
"A psi, do not use this table. Consult with regulator manufacturer for pressure drops and capacity factors. 
Pressure drops across a regulator may vaiy with flow rate. 

(2) CAUTION: Capacities shown in table may exceed maximum capacity' for a selected regulator. Consult 
TOth regulator or tubing manufacturer for guidance. 

(3) Table includes lo.sses for four 90-degree bends and t^vo end fitdngs. Tubing runs with larger number of 
bends and/or fittings shall be increased by an equivalent length of tubing according to the following equa- 
tion: L = 1.3n, where L is additional kugtii (ft) of tubing and n is the luunber of additional fittings and/or 
bends. 

(4) All table entries are rotmded to 3 significant digits. 



238 



FUEL GAS PIPING 



Table 13-23 



Table 13-23 Corrugated Stainless Steel Tubing (CSST) [NFPA 54: Table 6.2(q)] 























Gas: 


Natural 






Inlet Pressure: 


S.Opsi 




Pressure Drop: 


3.5 psi 




Specific Gravity: 


0.60 




Tube Size (EUD)* 


FlowBesigniltion: 


13 


15 


18 


19 


23 


25 


30 


31 


37 


46 


48 


60 


62 


Length (ft) 


Capacity in Cubic Feet of Gas per Hour 


10 


523 


674 


1.080 


1,300 


2,000 


2,5S0 


4,920 


5,660 


8,300 


18,100 


19,800 


34,400 


40,400 


25 ' ■ 


322 


420 


6<)1 


827 


1,290 


1,620 


3,080 


3,540 


,5,310 


11,400 


12,600 


22,000 


25,600 


30 


292 


382 


632 


755 


1,180 


1,4.80 


2,800 


3.2,30 


4,860 


10,400 


11, .500 


20,1.00 


2.3,400 


40 


251 


320 


649 


654 


1,030 


1,280 


2,420 


2,790 


4,230 


8,970 


10,000 


17,4.00 


20,200 


50 


223 


293 


492 


586 


926 


1,150 


2,160 


2,490 


3,790 


8,020 


8,930 


15,600 


18,100 


75 


180 


238 


403